It's also possible that, after Spanish/Aztecs, the historical double-set well will run dry and it will be back to all fantasy (or maybe historical single sets).
I personally think that well will run dry pretty dang quick too. The limitation on historicals is that they tend to be kind of similar. Look at Rome vs Carthage: the two contemporary armies are pretty dang similar to each other. We really stretched making Alexander vs Persia different, but that's simply not going to be possible all the time.
One of the suggestions I made to Chad about the historical Mercenaries set was Greece between the Persian Wars and its conquest by Phillip of Macedon. During this period, Greek city states fought numerous wars against each other in a menagerie of shifting alliances. Starting with Sparta's victory in the Peloponnesean War, the pattern was: 1) hegemony by one city state fights a coalition of city-states 2) coalition wins, and soon a 'first among equals' city-state becomes the hegemon, 3) new hegemon fights a coalition of previous allies plus any former hegemons. The only constant was Persia, who kept funding the coalition against the established power of the day.
This period saw a lot of Greeks being exiled as their faction was ousted. Part time soldiers became full time mercenaries and fought for other Greeks, the Persians, the Egyptians, even in places like Carthage.
This would be a terribly boring two-army set, as you'd have a lot of very similar units. Even as a lone faction it'd have a lot of phalanx infantry, which'd make it pretty dull. However, as a mercenary faction, that'd be okay because like Monsters & Mercs it'd be meant to be Mercs first and a stand alone faction second. Each unit would be a different cadre from a different city-state (Athenians, Thebans, Spartiates, etc).
(btw, Chad gave me to okay to mention this, so I'm not spilling state secrets or anything).
Even Hannibal's Crusaders vs. Arabs--probably the best bet for another double-set after Spanish-Aztecs--suffers somewhat from this.
Yup. Not much you can do about it either. The Kingdom of Jerusalem is probably the most varied 'knights in armor' faction you'll get unless you go with a late Hundred Years War or Early Renaissance faction. Which might shade into Hawkshold at that point. Most feudal armies (England, France, etc.) will be pretty similar and not have enough units. Jerusalem allows to differentiate the units because they drew from so many different groups. But in truth its a bit of a stretch (the effectiveness of Templars & Hospitallers is probably the same), and even then it's still a close and hose cavalry army.
And many historical armies have too few unit types to make a full faction.
Which is why I think most historical themes will get translated into a fantasy setting. It provides more freedom in creating the units and making stuff up.
But fear not, I think there are potential ideas out there. I think the Amazons would make a very good fantasy faction. I also think a Celtic/Viking type barbarian faction is also promising.
