The World Of Perisno

Overpowered? Nah! Try to fighting a Maccavian Spearman Phalanx, that's even more absurd, awesome and overpowered.

Your household seems great

Some more:

Household Troops

2. Priests of the Dragon (household troop faction is Reiche de Drache [sp??])
The Priests of the Dragon are firm believers of the Dragon Gods (might not fit into lore but you can decide) and they are dedicated to them. They have temples and altars to the Dragons in almost every city of the Reiche, and they are a secretive organization. Whoever dares laugh at their "silly religion" will mysteriously disappear, although some say they become the Dragon Priest's slaves. Their armor and shields are supposedly made from dead dragon's scales and their daggers are supposedly dragon tooths made into weapons. They fight only for [insert Reiche lord name here], who is rumored to be the founder of the Dragon Priests.

Stats and Equipment:
Dragonscale armor (almost invincible armor)
Dragonscale greaves and helmets
Dragon helmets
They use in battle:
 Dragonscale Shields
 Dragontooth Daggers
 The Zweihänder (or any other weapon)
 Blessed Flail of the Dragon Gods (some special flail that only knocks enemies unconscious)
Stats:
Iron flesh 2 (low IF because of strong armor)
Power strike 6
They ride horses called Dragonmounts
Inspiration: Dragons of course
There would probably be only 5-6 of these in an army

3. The High Inquisitors (for Hakkon Empire)
No one can hide from the Inquisition of the Hakkon Empire. After expanding to Perisno, the Inquisitors immediately began to spread their influence into the mainland. The High Inquisitors serve no one except their leader [insert High Inquisitor Lord name here]. These guys will probably just be more buffed versions of the Hakkon Heavy Lancers.

4. Perisno Mercenaries
The Perisno Mercenaries have been in Perisno for years. They are hard men and woman who have lived through famine, disease and war, and survived. They live for nothing but gold in their pockets and food in their stomachs. They would fight for and against anyone, no matter how terrible to get what they want. When they heard of a king raising the banner of Perisno itself, they flocked to him [the player] to pledge their allegiance to this new king.

The Perisno Mercenaries could be like a Mercenary Company (like in the Silverstag mod or PoP), or they could be a kingdom reinforcement troop (don't think a mod has done that before). When the player starts his kingdom, he could immediately get 10-20 Perisno Mercs in his first castle/town and buy more later at his tavern (there could be a character there that allows you to buy only Perisno Mercs for a price). Which brings me to the idea of Perisno Mercenary Companies

PERISNO MERCENARY COMPANIES
There could be mercenary companies available for hire in Perisno, in taverns. Each of them would be very expensive, maybe 100,000 for one? There can only be 1 hired at a time but they cost no wages after hiring. Merc companies are lead by a unique NPC and follow you around once hired.  Once they are defeated, they will reappear in a tavern a month later. This is to balance them out, so the player cannot hire them excessively. These Mercenary companies can be hired by any lord or lady in Perisno (not sure how you will code this, because I have no experience in modding, but I would like to know if it is possible).

Mercenary Companies:
-Perisno Mercenaries (see idea #4)
-The Hakkon Rebels:
These guys can only be hired if you are doing the claimant quest for Hakkon or a vassal of Tolrania.
-The Tolranian Outlaws
Sorta like Robin Hood, basically these are an outlaw company you can hire if you choose to be a bandit (so negative honor, bad relations with Tolrania, etc.

Another idea is to make  mercenary companies parties roaming around the map for you to hire under the right conditions

Well, you asked for it!
I'm going to give you some more ideas.
Mercenary Companies Continued
-the Úlfheðinn (Berserkers)
These guys are a famous Volheere raiding company who make their money off pillaging and looting whole villages. They are sometimes hired by Hakkon lords to do their dirty tricks, but if they ever fail to be paid, the result turns ugly for the lord that hired them. They are famous for their strong berserkers, who go into battle swinging huge battle axes over their heads and wolf heads as their helmets. They wear bearskin and have markings on their bodies signifying themselves. These berserkers are feared throughout Perisno, and it takes a truly brave leader to stop/hire them.
To hire these guys, you need at least 20+ relations with the Volheere Raiders. Otherwise, they will try to kill you the moment they see you. (Writing this makes me think that it would be better to have roaming mercenaries for you to hire or kill for loot upon meeting certain conditions than to have mercenary leaders in taverns. It also gives me the idea: what if you can make mercenary company leaders your companions? Then you can make them lords for your own faction. Just a thought, but I think it would be cool).
the Elven Archers
These guys are Redwood elves who dislike living boring lives as soldiers. They instead choose a more adventurous path of life, becoming mercenaries for hire by human kingdoms. While those of their own race frown upon them, (the Council Elders have even issued a decree to execute their leader) they are admired by those who hire them. They fought in a famous battle between the Hakkon Empire and Tolrania, and played a key role in the victory of Tolrania. It is said their arrows rained hell upon the Hakkon Inquisitors and made them flee in terror. Whether this is true or not, the player must decide if the Elven Archers will be a valuable asset or a troublesome enemy. [More to come, just realized how many ideas I had!]

Minor Faction:
The Kyrian Empire (random name, change it if you want)
The Kyrian Emprie is an empire from a land far away from Perisno. They are looking for new lands to colonize and make their own, and they see Perisno as a perfect opportunity to expand their lands and bring in the Imperial Rule.
Inspiration: Based on Zheng He and the Ming Dynasty in China
The Kyrian Empire decides to send advanced scouting parties into Perisno so they know where to colonize.
- Each party has around 100 men and are numerous in the coast. They are hostile to all factions so their patrols get defeated frequently.
- They also have parties called "Kyrian Pioneers" who come in vast numbers (maybe 200+) and roam around all of Perisno looking for places to settle. They are weak but numerous, and in every Pioneer party there are a few elite troops (the Imperial Heavy Infantry and Elite Crossbowmen). Maybe there could be an event later where the Kyrians launch a full scale invasion on Perisno (would be very epic) and many lords (like 10+) invade. This would be like the Dark Knight invasion in the mod Native Expansion. The invasion is able to take towns and castles.

I think he is doing a hell of a job so far
Its fun going through it all 

Some more:

For Dark

-Worshippers of the Old Gods
These guys are a minor faction who wander around Maccavian territory preaching and spreading their religion on the Old Gods - not always peacefully. Maccavian farmers who follow the New Gods constantly dread the Old God preachers coming to their lands.
Inspiration: Roman Empire, and you can't count out the hundreds of hours I spent playing Rome: Total War!
The Old Gods preachers wander in small parties (around 30-50).
The army composition is usually:
1 High Priests/Priestess
10 Praetoriani (heavy infantry)
20 Gladii Velites (javelin-skirmishers)
20 Preachers of the Old Gods (light infantry)
So basically the Worshippers of the Old Gods (abbreviated WotOG) are based on ancient Maccavian beliefs and are secretive (Dark you can expand on that).

Which brings me to the subject of The New Gods Worshippers (tNGW)
These guys are the opposite of the Old Gods: They represent chivalry, duty, and order (taken from Maccavia Lore), while the Old Gods represent honor and war.
Basically the WotOG and the tNGW are always fighting against each other in Maccavian soil.
Army compositions:
1 High Bishop (leader)
10 Crusader Knights (heavy cavalry)
20 Crusader Archers (archers)
20 Pilgrims of the New Gods (light infantry)

The Maccavian King has ordered these two groups to stop fighting, because Maccavia must be united to stand against the other factions.
There could be a player option where he has to unite Maccavia supporting one religion (check out Sword of Damocles: Warlords for the religion system). Once Maccavia is united, they could get special Religion Troops that are very strong but hard to obtain.
For example:
Character creation:
Start in Maccavia
then: What religion are you?
-Old Gods
-New Gods
That's how the character creation will work.

There could be 2 Maccavian lords with religion household troops (if the lord follows the Old Gods devoutly, he gets Old Gods Household troops and the same for the New Gods Household troops).

.... EVEN MORE SUGGESTIONS: (I hope you haven't gotten tired of me haha)
Minor Faction:
-Tolranian Bandits (basically the Forest Archers in Native, their leader is kind of based on Robin Hood and available for hire (see above posts)
Nothing special about these guys, just a bandit faction.

Note: this suggestion is going a bit onto the fantasy side, so I don't know if you need it for this mod
Minor Faction:
-The Buried
These guys are basically undead. They were resurrected by an evil sorcerer soon after the founding of the Hakkon Empire, and ever since then they have been terrorizing Perisno. It would take a true hero to stop this new evil threat. Their stronghold hidden in a reclusive place, and is very hard to find. (Their lair would work like a bandit lair, and there is only one. After that is defeated, there will be no more Undead spawns.
Their lair is heavily guarded, and constantly spawns Undead hordes.
Standard army:
1 Necromancer (unique unit)
20 Undead Reapers (light and mobile infantry)
50 Undead Archers (archers)
50 Undead Blademasters (heavy infantry)
30 Undead Berserkers (heavy infantry)
20 Undead Cataphracts (heavy cavalry)
30 Undead Horsearchers (light cavalry)
Every army looks something like this, although the unique army lead by the true Necromancer is much stronger.

1 Necromancer (the TRUE one, this is an NPC character)
30 Guardians of the Tomb (REALLY strong infantry)
50 Undead Berserkers
100 Undead Archers
100 Undead Blademasters
50 Undead Cataphracts
100 Horsearchers

They are special spawns who can be killed for special loot.

Apologize if I have some errors in my writing, English isn't my first language.

I also have a couple of suggestions regarding the world map.

I think:
-Drahara should be the only faction on the desert.
-Switch Maccavia and Hakkon's areas to make it more lore friendly
-Tolrania should be near Hakkon

I also have a couple of suggestions regarding the world map.

I think:
-Drahara should be the only faction on the desert.
-Switch Maccavia and Hakkon's areas to make it more lore friendly
-Tolrania should be near Hakkon

-Drahara should be the only faction on the desert.

my thoughts exactly

-Switch Maccavia and Hakkon's areas to make it more lore friendly

Huh? Maccavia should be all snow and i think a island, right Dark?

-Tolrania should be near Hakkon

Why?

Watching the videos of the actual base gameplay, I suggest we do a total rework on the native to make it all seem like a whole new world, changing Steppe Bandits to Hill Raiders/Vultures, Desert Bandits to Desert Trackers/Rats, Forest Bandits to Tribals/Savages, Taiga bandits, to Fanatics/Heretics.

This will be done (Names pending). Also minor factions will be added along with Volheere.

I am Planning on creating a Mercenary/Bounty Hunter Faction based on the Maccavians inventive nature, the Arkenlight Order. They use several contraptions, from Battle Claws to Dartshooters, they also use leather goggle masks, wrenches, even maybe some Air Ships?

goggle masks? air ships??
Interesting. Right now, i am staying away from anything that flies. God knows i don't have the experience