@dynamight picodrive has always been the default megadrive emulator for pi 1/0. pi1/0 versions of retropie don't really have any emulators/software related to other pi models installed by default. that's why there's different image downloads.

emulators can increase in accuracy and requirements, but the ancient versions used for pi1/0 shouldn't.

@good_punk Not sure what tweaks Dosbian added to their Dosbox versions, one thing I see is that they've disabled the KMS GPU driver in their config

[pi4] # Enable DRM VC4 V3D driver on top of the dispmanx display stack #dtoverlay=vc4-fkms-v3d max_framebuffers=2

Either Dosbox or Dosbox-Staging should be ok, start with the default configuration and try to find a fixed cycles value that's suitable for each game (on ARM, cycles = auto doesn't work so well). You can ask in the Dosbox-Staging topic or look in the Dosbox Staging wiki for pointers.

@aillerk please provide a verbose log (see https://retropie.org.uk/forum/topic/3/read-this-first)