I disagree with teh UW idea, but think their should be the idea of 'better' and 'worse' units. This would espeically help make an arms industyr important, since everyone would like an Abrhams.
First, they need to multiple all the stast(including movement) by at least 10. Then gradients are more distinguishable.
Second, now all unit evolution follows tactical 'classes' and those units evolve as units in that tactical role.
Thirdly, new technology might improve a particular class. Usually in these situations you have a choice in implementation how to improve the class relatively. This might be a choice between 'mobility' and 'attack'.
The combat system would also be modified a little bit. Now that movement is seperated into 10s(each 10 would be 1 square on the map, so 8 would be 1 spt and 12 would be 2spt). Movement would determine how easily retreats occur and possible bonuses in open terrain(if you were way faster).
Also, because of this new movement model, there would be a couple extra options when you choose your attack move. First their would be skirmish, which is fight till you take damage and then fall back. This would be good for fast archer types. Next, for cavalry and armour units, there is breakthrough. This would only apply if there was enough MP. This risky attack will carry the cavalry units past the current line. Infantry who then fill the gap push the defenders automatically to either side.