@the496rocket please, try to fill the form in the read this first post.
There must be something wrong in your setup. RetroPie on a raspi3 with decent peripherals can run smoothly any game from the 8/16-bit era without any tweak. Just install, config input, put your ROMs and play.
[Footnote: OK, maybe 3D games, like StarFox (SNES) and Virtua Racing (Mega Drive), can stutter a bit. But the games you mentioned should work just fine.]