Mercenaries vs Pirates vs Ninjas vs Vampires vs Werewolves.
That would be an interesting game ... given certain limitations. (and perhaps a bit of modding)
Namely, werewolves would have to be easier to get and more useful (the modding part) ... as for the others, the vampires should be banned from casting death spells ... and probably no one should use religions.
*Or rather, no magic or divine units ... only Boarding Parties + Ships, Baron + Wolves, Vampires, Mounted Mercenaries, and Ghosts.
Perhaps the Ghosts could also use some melee + Seige (allowed for everyone), but premarily using their "main event" unit.
Religion could be used ... just no Priest units (only adepts at most).
Probably on a Big and Small map with multiple continents and Island region not separate ... or on Low Sea-Archipelago or Snaky Continents.
Then another person could play as the Bannor to be the papacy/Church/Monster Hunters. (Elohim being possible alternative, but Elohim are too nice)
Suggested Races->
Ninjas- Sidar
Pirates- Lanun
Vampires- Calabim
Werewolves- Doviello, Svartalphar, or Kuriotates
Mercenaries- Hippus
Church + Peasantry- Bannor
**If the Werewolves are Kuriotates, they could also use the furry Recon line alot.