With the buff to the Bazooka all tanks below BR 4 are really easy to destroy not only to tanks but also to the infantry. Any chance that the tanks had of stoping the M1 frontaly ceased to exist. So what is keeping them in BR 3?
The only good thing about them is their gun and the penetration it offers. But then you need to keep in mind that allied tanks have about twice as much armor so not only is the lower penetration of the allied guns not a problem until you reach BR 4. But also is the higher penetration deminished by the increased armor which in turn is only a moderately size advantage at that point anymore.
And if you want to tell me that the worse penetrating long 75mm would be OP as it can kill tanks above its BR then remember that this applies to any BR 1 allied tank which have no problem penetrating any of the current BR 3 axis tanks without having their BR inflated because of it.
The long 75mm is just worse against infantry than the short ones they already have so even that should not be a problem.
So what else about those tanks is even good?
They dont have the commander mgs like the better BR 3 versions (or any for the stug F) and their armor is already not existant even in BR 2.
In most of my matches the effectivity of the tanks nose dived the moment a single player remembered to use their AT soldiers (which have great range thanks to the M1 and due to the buff dont need to be very precise anymore).
The 76mm BT 7 would be most comparable tank at that BR already in game and it even has better mobility than a panzer 4 so it should perform even better than a F2.