You are completly missing the fact that AVRE is not map dependant what so ever.
Unlike ST, AVRE can always just pop out from any sight blocker (even with some micro with turret already rotated), deliver the shot move back, while ST requare either have to move in and out in a strate line or he would have to rotate increasing its firing time. Also lets not forget that AVRE benifits from Hammer speed boost aswell.
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Few points:
Apart from collision inconsistency, the decrew mechanic was removed. So its ridiculous veterancy now only removed with the tank itself. This made a) more convenient to use and reload whenever you want b) removed the ST sharing/multiplying exploit.
While AVRE is more flexible ST is able to fire from the fog of war and with vet it selfspots and shoots from 45 range.
Yes, AVRE gets a lot of armor, but ST gets some armor with vet as well as health. 1440 health and 242 frontal armor is nothing to sneeze at. But imo unit like panther helps a lot with dealing with such unit.
Also lets not forget that UKF is a awkward faction.
While the projectile became slower the delay between shooting command and impact is almost the same. Used to be 1s for shell to hit 40m and 3s delay. Now it is 1.6s for shell to hit 40m and 2.5s delay. So 4 vs 4.1s. I agree that Shell speed is important, but if you screwed with detecting prepatched ST you almost certainly done (shell could collide), not you can sort of react, but again, if you screwed with detecting new ST, you still are certainly done.
As an anecdotal example Duffmann used to spam this doctrine a lot before the commander patch. He used ST, but never liked it. Now he think it is way too good. Same with Siberian, Jibber, BaoLiang, Elpern. Although I can't provide any evidence they said it. + we have ridiculous pickrate of the commander. Pretty much if you are not a SOV without a "Mark Target" you gonna have a big problem.
Here are my words that sums up my opinion about nuking units:
The unit is toxic and nerve racking to play against, especially vs double rax build. Nerve racking and toxic destroys the mood while playing the game and I'd like to have fun while doing so.
This is similar situation like with ISU, that used to be completely broken (in teamgames including 2v2), except with ST you need to pay 5x attention during a game, or else you have a good chance of losing it.
Units that are in the conflict with the core idea of COH2 as an RTS (unit preservation) should not be highly effective or nowhere near meta, regardless of which faction owns one
So pretty much I'm ok with AVRE and ST at any level below OK and hoping a lot of people share my sentiment.