These hacks remind me a lot of Hummer Team's Famicom ports of the MK games, where the rereleases added lots of repeats for no apparent reason.
Also, call me crazy but I think the SNES one is actually a homebrew hack. Worth pointing out that every now and then, pirates release homebrews (for example, they released Sonic Megamix on cartridge without permission) so don't assume that just because it was released on a cart, it was made by pirates.