I'd like a "Northwest Frontier" Mod, late in the first half of the 19th Century,
Major factions would be
John Company (The Honourable East India Company)
The Pure (Sikh Khalsa)
Queen's Army / Sahib-log (British Army and imperial administration)
Minor factions would be
Kashmir
Afghanistan
and of course several variations on bandits, eg Thugs...
ONLY recruitables are irregular cavalry and infantry. EIC and Khalsa regulars and British Army troops would be assigned to AI parties by reinforcement script only, and the player would ONLY get these troops if they swore fealty appropriately, and then they would also be "issued" along with lord-missions. I can give you the script for this if you like...
irregulars however could include such colourful things as Skinner's Horse, the Guides, gorrachara, Ghazis....
A lot of scene building would be necessary.
current 'strategy' AI of native would be suitable, as the frontier was in a constant state of low-level war, marked by occasional full-scale campaigns.
add a few bits of artillery and the formations kit...