Whirlwinds, Tankbustas with barrage doctrine, fire prisms, big trakkz, chain stun scouts, killa can rockets (and also why do killa kans do true damage? This game is desperately in need of a third damage type and two more armor types to resolves nonsense like that), etc.
There are too many ways where bs can happen and you can lose your entire army (even when spread out properly). Whirlwinds are particularly bs since they can blind fire on your generators and kill them. Once solaria is out it is far too common for SM players to just hide behind lines of devastators and then spam whirlwind fire. Because of these mechanics players are incentivized to go for these types of tactics while hunkering down since the player who is attacking loses the initiative on setup teams and general unit spread.
So it favors these protracted BS-athons where for an hour each side fires off whirlwind spam, big trakz, and fire prisms/wraithguard. It is not what I would call fun. The early game otoh, is quite fun. But once whirlwinds start coming out and the dreaded 9 or 10 elites come out, gameplay turns extremely stagnant.
I love this game. But I won't be playing until these balance issues are fixed. It is too aggravating.