I don't disagree at all with this; but PFs are doctrine units, not mainline.
However, my point was, that PGrens were unused before this patch because they came too late to be good. Forcing an AI upgrade would mean that when they arrived, they would be (performance wise) worse than before, and require additional resources to become as good as they are now. This would entirely offset the resource/time saved by the current BP1/T0 setup.
While I see your point, PGs AI doesn't scale nearly as well as other mainline infantry units like double-bar rifles or double-bren IS. If this is a concern, then basically all mainline infantry needs to be re-worked.
While pfusies are doctrinal, they're definitely also mainline in every sense of the word if you give them g43s. They're reasonable to reinforce at 25mp, cheaper than most other mainlines except volks and cons actually, have a good squad size, have weapons that are essentially effective at all ranges, have a grenade, and have a snare, and they aren't prohibitively expensive in any way except having to pick a doctrine to use them. All but the very last could describe basically all other mainlines.
PG AI still scales fairly well, and scales at that rate for free unlike rifles and sections.
@OP I voted they should remain as is currently in live because I do feel that having
only schrecks as AT is a pretty decent risk, and gets countered hard by good LV play (except if you're brits and not using lend lease rip). Not having access to paks can really suck sometimes and personally I'm pretty wary of skipping T2 because of that.