at 2nl a 4bet is usually a shove though ,but savvy's said that he's flatting QQ some of the time and i presume AK as well, therefore not 3betting aggressively enough to get shoved on by random shit.

folding TT and JJ is a side effect of 4 betting with nittier players folding them , but its compensated by the fish calling and incorrectly set mining pre , chasing flushs with suited cards, and straights with connected cards which they'd likely fold to a shove.