Good calls, Xelee. Light Cav could indeed evade, and why not foot skirmishers? Due to the very nature and scale of the game, skirmishers wouldn't be too different except for their lightness, training and doctrine.
I'm imagining "normal" foot units in this scale simply adopting a skirmish formation (something like this)
http://www.roman-empire.net/army/skirmishing.html , and units not holding formation in a fight, ending up being a big brawl (ala what you see in Braveheart).
Do you happen to know the minimum unit size where close formations actually start being relevant? Is it in about century sized units?