By 1942 Germany had done a fair bit of work on developing 30 ton chassis as replacements for the Panzer IV that later evolved into the VK3002 project and 45 ton Panther with it's host of technical issues due to being seriously overweight for what the chassis and parts were designed for. Looking at the 30-40 tons chassis that the Soviets, US, and UK all fielded in WW2 it seems like there could have been a perfectly viable tank in the 35 ton range that the Germans could have fielded by the end of 1942 with relatively quick updating of the VK3001 project by adding sloped frontal armor and wider tracks, plus a somewhat bigger gun than the Pz IV F2, but less than that of the historical Panther to avoid the weight increase. Looking at Guderian's proposed Mehrzweckpanzer, which pretty much translates to multi-role armor, the basic layout seems to be pretty solid for a 35 ton tank chassis:
The only difference I would add would be a 75mm L/60 gun initially tested for the Panther based on an existing FLAK gun design (later increased to an L70 gun). The frontal armor of Guderian's 28 ton design was 50mm sloped to 55 degrees, which was better than the T-34/85. Technically speaking I see no reason why it couldn't be in production by the end of 1942 and be pretty technically sound at 35 tons, as the original VK3001 tank was expected to be 32 tons (i.e. the weight of the T-34/85, M4 Sherman, and British Comet tank). Certainly it would be far less problematic than the much heavier 45 ton Panther.
So what if Albert Speer talked some sense into Hitler and instead of the Panther built a 35 ton tank with the layout of the Mehrzweckpanzer above with 75mm L60 cannon and 50mm frontal armor sloped to 55 degrees, while then taking all the time needed to properly design something much better like the E-50?
Would something like that have been in production by December 1942 without significant technical issues? Could it be produced in greater numbers than the historical Panther and would it have been able to stand up to the standard enemy tanks of the 2nd half of the war? The 75mm L60 gun would have been roughly equivalent in performance to the British 77mm QF17 Pounder (minus APDS rounds).
Thoughts? Other than of course the standard 'rearranging deck chairs on the Titanic' and this won't change the outcome of the war stuff.