This seems to stem from the fact that the SDL2.dll was compiled with a different compiler. When I build all with the same, it works fine. Bug can be closed I guess.
It seems like the overlapping import table parts are caused by strip. But without strip the resulting executable also imports CryptAcquireContextA & CryptGenRandom from SDL2.dll, which fails. Best regards Dennis
Overlapping import tables with executable built with mingw-w64-gcc 9.3