playing through pre-1.1 it was all Magic, and only magic. My sov army would just run through and clean house with some token wolf riders or what not, who never did anything, as the opposing armies were mowed down long before they could advance into attack range, haha.
i don't have much experience with the current version, though. the universal mana pool should definitely change that tactic, as it was way way overpowered. you barely had to make any soldiers, as all you needed was two magic casters to summon several armies of elementals--which had no upkeep and were more or less immortal--that could run through and tear up most any army.