Teaching the AI limited group/team tactics in general would be a worthy, if potentially difficult, addition.
Maybe tags of some sort could be applied to mecha, and they could influence(but not completely determine) the general type of mecha you get in encounters. An average group would tend towards a melee-heavy mecha, a couple of generic gunners, and a heavy weapons/artillery mecha for example(Not saying this is actually an ideal group, just an example) and the RNG might bias itself towards making this group by tweaking the chances of each mecha being chosen based on it's tags.
The downside is that any 'generalized' mecha who might suit lots of tags would be chosen more often than specialized mecha....maybe each tag could also get a power rating to determine its over-all value in that role? Artillery 65 would be picked for the "Artillery" role more often than Artillery 15, for example.
Maybe I'm just over-thinking things. But something like this could also be applied for generalizing what that mecha actually does on the battlefield, too. An artillery-tagged-mecha would tend to hang back and fight from a distance, while a melee mecha would try and get in your face. Not exclusively, but in general they could tend towards their specialties.