And people make T-34/76 Sherman and Cromwell. Do you actually have a point?
If you need me to spell out why good players prefer getting P4s means Tier 3 is pretty good (as well as your own admission that the stug is OP) then this conversation is going to take a very long time.
Is your opinion that Ostheer Panzer IV "so good" that they do not need a better tank?
No, it is my observation that players better than I opt for tier 3 and specifically the P4 -- instead of tier 4 and the units it unlocks. They also explicitly say as much when asked.
My opinion on your question is... blank since OKW is my prefered axis faction and I have about 5x as much time with OKW than Wehr. Who cares what my opinion is? Play the way you think is best.
I'm not into stupid nitpicking arguments, if you want to turn this into an endless back and forth then let's just skip the whole thing and you can pat yourself on the back right now having slain another vile noob on the forums.