Hm I would not be very keen on this. I mean, yes tommies were nerfed and then buffed again, but they are still potent en mass. Just imagine these hordes running around covered by smoke. No thanks lol.
The newest buff to sections is minor and come because the previous neft has been considered too much. Yet, sections are kind of ok now as an unit but the faction has gaps in it lineup which need to be fill, smoke is one of those gap.
As said, the ideas here is pyrotechnics upgrade will allow section to throw marker
For a smoke barrage from base. The main purpose of it is to deal with Mg garrison, with a significant delay for the gun in base to make ready, plus a long, share cooldown with HE barrage, i dont think this can come anywhere near OP.