Profile of Hannibal

StuG and JP are a testimony too how much Brits changed the game. Axis usually did not face heavy armor, because standard tanks of Soviets and USF are relatively light. So these two units worked well against all allied tanks, and Panther was only needed as a heavy brawler and break through unit.
For allies, only Brits can field heavily armored tanks which makes team games more difficult since your JPIV might work or not, depending which enemy your currently face in that moment.
On the other hand, a JP4 has a decent 70% pen-rate against a churchill and drops to about 50 % vs real heavy tanks like pershing and IS-2. If your enemy goes for a ~230 fuel unit, I think it should be alright to build a 185 fuel Panther.
StuG and JP4 currently have the role of fighting off mediums (and the JP4 also can fight off other TDs), which they are actually pretty good at. I think the split is fine, since Axis are the only two factions who two TDs. Specializing them in one cheaper alternative fighting off mediums and the other costly alternative fighting off heavies is a good thing.