What happend with the new battle system?

After the new update, 4 tanks/marines could lose against 5 militia (32 att vs 20 def) or 9 could lose against 8 infantry (72 att vs 56def)

Battle system haven't changed in months, apart from critical hits, which are not really that important.

Bad rolls are a bit more common with critical hits, although it isn't as bad with the critical chance at 5% instead of 20%.

Also these kinds of things could also happen pre-update, it was just less likely to happen.