The Auto Union engines were in front of the rear axle so they were mid-engined, the wayward handling was as much to do with the monstrous power and the stupid swing-axles as much as horrid weight distribution.
None of which detracts from your point, which I completely agree with. Apart from the coincidence of the engine position, there is almost nothing in common between the two. A monster V12/16 versus the little Climax engines. The first 'modern' chassis layout (borne of using bike engines and chain primary drive on the F3 cars) versus a chassis compromised by aero and packaging such a huge engine.
Oh, and I forgot to say thanks for providing such an entertaining thread. Any post with 250Fs gets my vote.