so i'd be wary of putting too much stress on bad engineering as a detriment. if they'd been built by properly employed workers motivated to actually do their best work, the late german warmachine would have been a nightmare to face.
Nonetheless, there is still a "bad engineering" issue with these tanks. The Panther had the transmission & drive train designed for a 30t tank, not a 45t tank it became. The Tiger I was already slightly under powered; the Tiger II was several tons heavier & still used the same engine. Even older tanks like the Pz IV suffered more frequent breakdowns. Added to the Panther (& presumably Tiger II) issues was the fact that if you blew the transmission, you had to remove it through a small plate in the upper hull which also required partial disassembly of the drivers compartment to do so. A transmission swap on a Panther could be an all-day exercise, whereas on the Sherman the entire nose with the transmission could be removed & swapped in a few hours.
I have no doubt that some of these German tanks were very good performers (the Panther, when properly working, was a very good tank, with better mobility than a Sherman or T-34, better protection, better gun, better speed, etc), BUT on the other hand there were some pretty big flaws in its design (IIRC the first & only Bn level assault by Tiger IIs during the Budapest engagement, saw nearly half of the Bn drop out due to mechanical failures in the march up from the assembly area, per the book
Sledgehammers). In retrospect the best way to kill Tiger tanks was to force it to engage in a road march of more than 10mi! There was a big reason why the Germans preferred rail transport whenever possible...
Yet many of these tanks had a very outsized impact on battles, but especially on the
impressions of the participants on either side.
For those reasons I tend to be pretty skeptical about claims of the "best tank" or "worst tank" especially in the European theater.
Damon.