Sashimono aside, I will say that such a mod would instantly win my support, even though I found Total War (Empire and Napoleon) so-so.
You should give Shogun 2 a try then.
- - - - -
Rather than fighting for control of human towns (since there only one in Gensokyo), everyone's fighting to control the most plentiful and disposable part of Gensokyo, fairies. Or, more accurately, spiritual lay-lines where fairies tend to cluster and other important locations in the realm.
Also, Generals and Leaders are not killed, they merely retreat to the faction's capital to recuperate for a bit. There are "free agent" characters they may want to join a faction, provided certain conditions are (or are not) being met.
That said...
CirnoLeader: Cirno
Other Starting Generals: The Three Mischievious Fairies
+ Improved morale for all Fairy Bands
+ Reduced costs and upkeep for all Fairies
Religion: Shinto-Hakurei
FujiwaraLeader: Mokou
Other Starting Generals: Keine
+ Improved morale for all Human-lead units
+ Reduced costs and upkeep for all Human-lead units
- At war with Houraisan
Religion: Shinto-Hakurei
HouraisanLeader: Kaguya
Other Starting Generals: Eirin, Reisen, Tei
+ Improved morale for all Rabbit Brigades
+ Can recruiut superior Rabbit Brigades
+ Reduced costs and upkeep for all Rabbit Brigades
(Master, where did all these rabbits come from?)
- At war with Fujiwara
Religion: Shinto-Hakurei
ScarletLeader: Remilia
Other Starting Generals: Sakuya, Meiling, Patchouli, Flandre
+ Recruits Fairy Maids instead of Fairy Bands. Fairy Maids are cheaper, but have lower morale than ordinary Fairies.
+ Increased loyalty for all generals
Religion: Shinto-Hakurei