I like it!
One observation would be that skill checks with "equal or beat" (if I'm correct in interpreting that as "greater than or equal to") have the strange side-effect that the higher the stat, the worse the unit, which is unintuitive. That's why Fighting Fantasy -likes among others do skill checks with "roll under" stat.
If I get to put this on a table at some point, one addition I think I'd go for would be some notion of "speed" for the units, as in, how often they get to act. Also maybe some kind of flanking rule? Everybody loves flanking.
cheers!