In my opinion, SNES and Genesis should be different categories. For the fastest speed on each, SNES takes 28 frames to go down a second of game time, where Genesis uses 25 frames. That makes for a 12% inherent advantage, similar to the advantage NTSC has over PAL, and plenty of games have separate categories for PAL.
In this case, the differences between the ports is more substantial than that as well -- the AI on Genesis seems to be more aggressive, and the block and steal mechanics feel different.
I agree with that, I've seen the way the snes version is played.
As well as when I played through genesis, the AI did seem more aggresive even though they were set on very easy. Different categories on here can be difficulty and system being played on.