That would depend on your luck, and your Pretender. I usually pick a Pretender able to take provinces without breaking a sweat, thanks to a couple of spells (Invulnerability, Mistform, Mirror Image, Body Ethereal, Personal Luck, Quickness, Breath of Winter, Soul Vortex and Fire Shield among others. Oh, and Air Shield too. A Virtue with Invulnerability, Mistform, Body Ethereal, Quickness and Luck/Mirror Image works quite well, among other things.
Otherwise, Centaur Warriors for Pangaea should do the trick, perhaps massed longbowmen for Man, maybe the Elephant/high morale troops combination for Arcoscephale and Caelum, or even assassins... I am not too sure of the specifics though, as my troops usually do poorly against the independents. The only time I did manage to slaughter independents was with Arcoscephale and a Fire-9 blessing: the Pretender, a priestess and ten Heart Companions had the firepower to take down knight provinces while only taking a few losses, and Fire-9 is cheap. Problem is, that sort of setup won't be much of a help later on in the game, as I found out.
