A video that I commonly direct people to for a good overview of tank production in WW2 is here.

While the mainstay German tanks like Panzer III and Panzer IVs were not strictly speaking overengineered, they did suffer from the German production pipeline not being properly industrialized or designed for scale.

The Soviets quickly adopted and adapted to copy the American production line, with the modification that factories were centralized rather than relying on very much secondary production.

T-34s, especially wartime production T-34s were not great tanks. They did enough to blunt some of the fighting, but the undersung hero of tank combat in WW2 were old fashioned anti-tank guns, which while far less exciting than tanks battles, took out more tanks than enemy tanks did.

There is really no production choice the Germans could have made in the mid war that would have turned the tide. They simply hadn’t started the war with the appropriate factories and their ability to build those factories continually degraded. There were too many cooks in the kitchen regarding tank production, so even if an individual did come up with a great plan to restructure production, it would be mired in the factional infighting of the German military.

While there are stories of workers T-34s driving straight from sieged factories onto the battlefield, I’ll emphasize the fact that those are stories, and are apocryphal at best. The Soviet Union after WW2 was very eager to spread aggrandizing stories about the great fight.