I3BrigPvSk
The Viking
I go with a yes and no approach on this one.
Producing complicated stuff was a problem for Germany but not because they produced it but rather they could not properly test it before putting it into frontline service.
Let's face it had they known the limitations through testing of the Elephant it probably would never have made it off the drawing board.
Personally I believe Germany should have focused on the Panther in small numbers and spent the majority of its resources retooling the Pz IV into the Jagdpanzer IV, this would have given them a cheap, powerful armoured vehicle with good crew survivability characteristics that could have been mass produced while still producing a high-quality MBT capable of footing it with anything on the battlefield.
One thing I think people tend to forget is that despite Guderians wanting to focus on the PzIV it was outdated and would have been a death trap up against the tanks of 1945.
I also think they really needed to put some focus on the Luftwaffe fighter wing as early as 1939, it more or less just stopped development between 1938 and 1942, but until they could wrestle back some level of air parity over Europe the war was as good as lost.
As for the surface Navy, despite its poor combat performance with the exception of my favourite ship the Prinz Eugen it was not the waste of resources people seem to believe it was, the number allied resources tied up in making sure the Tirpitz didn't break out was phenomenal, far greatter than the amount of resources that went into making the Tirpitz.
As for more submarines, not a lot of point in more tanks, subs or aircraft unless you have trained crews to operate them, and by 1944 the Germans didn't, therefore, they needed quality rather than quantity, they needed to keep inexperienced crews alive long enough to become quality.
I am sorry for the late reply. I have read criticism about focusing a lot of resources on the surface fleet when these can have been used to produce subs and having more sailors for the sub fleet instead of challenge the RN like they did