It used to be balanced: when buying a second squad was expensive and slow and volks were crappy. They also had less resource income to slow down their tech a bit. (Which meant gaining extra map control at the start of the game didn't snowball.) They also had Luchs come out a few minutes later, which was more balanced. (Luchs was a 9-11 minute unit before, now it's a 6-7)
I don't think sturms are the root of the problem, although making them cheaper continues to be a full retard design decision. (Kind of like 210 mp Sappers)
Oh my, where to start with your incomplete statement of "facts" ?
Well, lets take it from the top then: volks were are also made more expensive, their vet 4-5 bonuses were nerfed.
The OkW teching price also got increased, aswell as fuel cost for several units (basicly the same model as before, only in a limited amount of units)
And last, but certianly not least of your incomplete analyses: Luchs comes out at the same time as the t70 and the stuart, therefor it's a good timing with the other light vehicle's/tanks.
As for sturms being cheaper: they were horribly, horribly cost-ineffective before the changes made to them. There was a reason no one build a second sturmpio squad and it wasn't because everyone couldn't think of such a insane idea to do it...
1.US mine is a doctrinal choice, which is a big, big difference.
A. he was talking about the sov mine, which to my understanding is not doctrinal....
B. the USF, UKF Sovjet and OkW shu-mine are all the same, with the same retarded 33% chance to cause heavy engine damage (and we all know: heavy engine damage = ded tank)+ the usual oneshot squad capabilities.
C. Since volks schrecks are a thing (mandatory and no-brainer upgrade, how i hate it) and shu-mines come on rather expensive sqauds, there is less usage of them and they are used vs larger squadsizes so calling them "the best" might technically be true, but i'dd say there is more too it then that.