The QF 75 was made with the express purpose of using US ammunition. By the time the QF 75 was introduced, fusing issues with M61 APHE were largely resolved, so they did actually use this round in fair quantity. It’s not fair, in my eyes, to describe representing these vehicles more accurately as “slopifying”.
This argument isn’t useful anyways since the update hasn’t dropped yet, so you can’t act like they’ve been exploiting APHE this whole time when grinding the British tree.
The 6-pdr offers noticeably better RoF, penetration, and has a flatter shell trajectory compared to the QF 75. Tanks with it aren’t going to become useless just because the QF 75 gets to perform at its intended level, so that’s not a good rationale for handicapping the 75 mm to be direct downgrade to the 6-pdr.
If the QF 75-armed tanks do end up being stronger than their higher BR 6-pdr counterparts, just move them up. I already proposed how that might look for the Valentine XI such that the Valentine IX would still serve a role.
Furthermore, the Valentine IX and Cromwell I should actually have even better guns that currently. They have 6-pdr Mk.Vs with the stats of the 6-pdr Mk.III. They should have comparable performance to the Churchill III, which actually has the opposite issue currently.
Valentine Mk. IX Wrong 6-Pdr
Cromwell Mk. I Wrong 6-Pdr
The Sherman II does have a stabilizer and .50 cal. that you can’t find on any QF 75-armed tank iirc. The former is a very strong asset that would allow it to kill a Cromwell V first most of the time in a hypothetical encounter. It would come down to a matter of player preference, or what type of map you’re playing on.
I can still see your point however. I think the Cromwell V could go up further to 4.0 now, in which case, the Sherman II at 3.7 would still serve a purpose in the tree.

