I suppose its the state of call in tanks at the moment, by going no tier, you often have 300+ fuel stored ready to spam.Since the patch I always go Tiger/ Elefant combo in 2v2 as Germans.
Usually I´ll mix in a StuG or two on the way to the CPs.
The two times I did build T4 the Panther was obliterated by Su-85s it couldn´t reach or Sherman-spam. With a Panther that
- has less range than the Russian tank hunter,
- less health than pre patch,
- less armor bonuses than other tanks at vet 2,
- is now more expensive,
- can´t blitz
and a nerfed Panzerwerfer there is no reason any longer to go T4 as Germans. You are better off with Tigers and Elefants late game.
In all honesty German T4 is a joke.