First war I was in I got 3 bronze, one silver box, and zero cards, just sims, keys & tokens, like you.
2nd war - got a couple upgrade cards, enough to upgrade comic hand to level 2.
3rd war - got dozens of upgrade cards, which unlocked 2 new disasters and put a couple more to half way upgraded.
Dunno if it's just random, or if the rewards ramp up the more you play.
