It was toned down already by quite a lot.
And it doesn't one shot anything that isn't
1) stationary
2) close in front of it
3) clumped up hard
I see more squad wipes from Zis than from a mortar in high ranked games, i don't think this is a good concept. Zis > than mortar has no sense. Anyway, if i have an mg, maybe clumped up facing a soviet at gun, i don't think it deserves a good chance to be hit by the first or the second shell of the barrage and then wiped. I'm curious to find some zis barrage stats for a comparison with 120mm mortar.