Hi! I'm a big fan of the series, and I'll just throw some random ideas and see if I can get them coherent enough.
I had a list of unit types that I had planned out for a Medieval 2: Total War:
Code:
Midkemia (Humans)
Yabon Heavy Foot (Heavy infantry)
Krondorian Lancers (Heavy Cavalry)
Shamata Redshirts (Heavy infantry)
Keshian Dog Soldiers (Heavy infantry)
Valeman Mercenaries (Heavy infantry)
Valeman Skirmishers (Light infantry)
Keshian Charioteers (Cavalry)
Hadati Mountain Fighters (Light Infantry)
Can hide in grass
Bonus in snow or rock
Izmali Shadow Warriors (Light Infantry)
Can hide anywhere
Kingdom Archers (Archers)
Kingdom Crossbowmen (Archers)
Dog Soldier Archers (Archers)
Roldem Marines (Light Infantry)
LaMutian Infantry (Heavy Infantry)
Knights of St. Gabalt (Heavy Cavalry)
Armengarian Mounted Infantry (Light Cavalry)
Keshian Inner Guard (Heavy Infantry)
Ashuntai Horsemen (Light Cavalry)
Ashuntai Mounted Archers (Light Cavalry/Archers)
Jal-pur fighters (Light Infantry)
Can hide in sand
Bonus on sand
Krondorian Royal Guard (Heavy Infantry)
Natalese Rangers (Archers)
Can hide in grass
Bonus in trees
Krondorian "Desperate Men" (Light Infantry)
Can hide in grass
Can disguise unit
Kingdom Lancers (Heavy Cavalry)
Armengarian Heavy Foot (Heavy Infantry)
Kingdom Spearmen (Spearmen)
Quegan Pirates (Light Infantry)
Kingdom Footmen (Heavy Infantry)
Imperial Tracksmen (Archers)
Can hide in grass
Bonus in trees
Trueblood Inner Guard (Spearmen)
Yabonese Mounted Infantry (Light Cavalry)
Thunderhome Nomads (Light Cavalry)
Heavy Infantry
8
Light Infantry
9
Spearmen
2
Heavy Cavalry
3
Light Cavalry
5
Archers
6
Other
1
As for the factions, I think splitting the Kingdom in two has it's merits, for one, it gives more faction choice.
So the factions I can see are: Kingdom Western Realm, Kingdom East, Kesh, Free Cites and Tsurani
Bandits would consist of Woodland\Mountain Moredhel, Quegan Pirates, Durbin Slavers, Goblin bands.
Mercenaries would be various Humans, Elves or Dwarves. Perhaps an occaisional Moredhel?
Western Realm: Led by The Prince of Krondor. Mix of Kingdom soldiers and Yabonese Levies. Higher tier units include Krondorian Lancers, Guides and Hadati Fighters
Kingdom East: Led by the King of Isles. Mainly Kingdom Soldiers, as well as auxiliaries from the East and South. Higher Tier units include Royal Knights.
Kesh: Led by a Keshian General (since I'm assuming it's only a little bit of Kesh). Has access to Dog Troops, Desertmen. Higher Tier units include Truebloods, Izmalis.
Free Cities: Led by a Councilman. Mainly militias, with some trained troops. Higher Tier units include Natalese Rangers.
Tsurani: Led by the Supreme Commander (on this side of the rift, at least). Access to heavy infantry, with some rudimentary calvalry. Higher tier units include Death Oath Warriors, plus the high ranks of the Tsurani army.
I was thinking of cho-ja, but it seemed wrong for a human to "promote" into cho-ja.
The best time for this should be the ending years of the Riftwar. Mad King in the East, Tsurani pushing all over the place, Kesh boldly raiding up the borders, slavers raiding seaside communities, the West taking the brunt of the Tsurani invasion. Ditto for the Free Cities.
Edit: Rudimentary troop trees
Code:
Kingdom West 12
Kingdom Citizen ->Kingdom Skirmisher ->Kingdom Soldier ->Kingdom Seargent
->Kingdom Rider ->Kingdom Lancer ->Krondorian Lancer
->Kingdom Bowman ->Krondorian Guide
->Yabonese Levyman ->Yabon Heavy Footman ->Haditi Mountainfighter
Kingdom East 10
Kingdom Recruit ->Kingdom Militia ->Kingdom Man-At-Arms ->Knight-Lieutenant ->Knight Captain -> Knight Marshall
->Kingdom Captain
->Kingdom Archer ->Kingdom Marksman
->Auxillary Skirmisher
Kesh 11
Keshian Conscript ->Keshian Auxillariy ->Dog Soldier ->Dog Soldier Captain ->Trueblood Guard
->Dog Soldier Archer ->Imperial Tracksman
->Jal-Pur Desertman ->Izmali ->Izmali Honour Guard
->Ashanti Horseman ->Ashanti Warchief
Free Cities of Natal 11
Natalese Peasant ->Natalese Militia ->Natalese Levyman ->Natalese Regulars ->Natalese Veterans
->Natalese Horseman ->Natalese Cavalry
->Natalese Peasant Archer ->Natalese Archer ->Natalese Marksmen ->Natalese Rangers
Tsurani 12
Tsurani Freeman ->Tsurani Recruit ->Tsurani Regular ->Patrol Leader ->Strike Leader ->Force Commander
->Death Oath Warrior
->Tsurani Horseman
->Tsurani Archer
->White Robe ->Grey Robe ->Black Robe