Why are we concerned with historical accuracy?  Samurai vs Arabic cavalry?  Milanese plate vs wedding dresses?  Side swords vs viking gear?  cRPG is the Deadliest Warrior Online.
+1 on the Roman stuff.  I study classics and it would be fun to get a couple classmates and play a few rounds with Roman gear.  This does highlight, however, the need for a short-range stabbing animation for short swordsman while they're also holding a shield.  Roman tactic, sensible tactic, and what's most missing from 1h combat IMO.