The OST P4J is just a clone of the OKW P4. You delay your P4 a bit and get better armour and scatter at Vet 0. The OKW P4 still beats the same units the OST one does, it just beats them a bit harder.
The 75mm Sherman is the best medium tank in the game, and that's because of its HE shells. It can freely toggle between being a generalist medium and an anti-infantry specialist.
There's a good reason the Easy Eight and 76mm don't get these, and it's the same reason the Panzer IV has better anti-infantry performance than the Panther: it gives you a reason to build both.
So it baffles me why they added an upgrade package that gives the 75mm Sherman the armour and health of a premium medium. The Sherman 75 Bulldozer beats and loses to the same units as the 76mm and Easy Eight, but it does so without giving up its anti-infantry firepower or the basic Sherman's shock timing.
Why did they look at all the Sherman variants and figure "hey, look at all these tanks with their own advantages and disadvantages, let's make one with all the advantages!" This thing only exists because they realised they could stick a dozer on a 75 with an upgrade and wanted to do it.
Strip this ill-convinced upgrade back out of the game. Put the E8 or 105 in its place in Urban Assault. Mechanized is fine with the 76mm.
I disagree, even if I agreed the upgrade was OP I don't think stripping units and abilities people paid for out of the game is beneficial at all. For instance as much as I dislike emplacements I don't want them deleted, just reworked.
Now to the dozer if it was a straight up "nobrainer" upgrade you would have a point.
But the reality is you're trading mobility on an already slow medium for extra survivability.So there is a trade off and decision making involved outside of the resource cost.
You basically can't flank with a bulldozer like you can with other mediums and this makes it more vulnerable to Jagdpanzer or stug compared to premium meds. Both of which pen it with ease even with the token armor buff.
The Soviet 85 can also be fielded at similar timing and is a markedly better tank. So for me there's not much issue. The dozer was judged to be OP on release and was balanced to its current state. It's already been "fixed".