serbs, albanians, lithuanians, irish, breton, basque, swiss, petcheneg, cumans, steppe people, alani, georgians, armenians, turks, uzbeq, afgan, volga bulgars,.... there is quite an arena of test for unit creators. the more factions are avaulable the more exact scenarios become, so one could restrain a very large map for the study of one campaign or a microregion...plotinus tried something exotic...
ps and there is one more point - we do not have a complete array of axemen, heavy javelin throwers, heavy mounted javelin throwers, nafta throwers, macemen, mace armed units in general, and we lack armed peasents (armed for war)