I think a similar result could be accomplished using a system akin to Civ 4s, have champions be able to tack onto units and the benefits be that they grant that specific unit buffs based on their specializations. The result being that units with champions attached are just as powerful as champions are now but have the quality of being a unit still and not feeling like one person is mowing down unit after unit on their own.
So for example have more specialized skills like "spear master" and all polearm units they are attached to get some kind of special bonus. This has the added benefit of not letting a single piece of gear make a champion a god.
I think a mix of the current champions and the general style champions would add depth to the game. Allow some Lancelot still super soldiers to mow down armies, but allow other tactician style champions to function differently as tactical additions. Plus that could be a loophole to allow units of magic users instead of single ones, give a benefit to special units design to complement a mage. So your mage has a unit of shielded spell resisters that give him high defense despite his/her poor gear defense, or conversely assistant casters who make his /her magic more powerful.