Thats a lot of excess work for a single costume. Not everything has to be that complex, Smash has spoiled us
Smash alt costumes aren't complex either? The most is the occasional different taunt or idle animation like with Inkling, and even that is only followed by like... the Koopalings' barely visible wands, and then nothing. I've seen amateur Smash mods do super simple stuff like the proposed ashed-up Reptar head here (one that comes to mind is a really silly PaRappa model swap over Ness that replaced Ness' ashed form in his intro with PaRappa's skateboard) - hell, Slap City replaces a lot of characters' weapons depending on alts, like Bees' cards over Frallan's pills - Masked Ruby's Human Fred alt outright gets an
extra weapon (Ruby usually only has one sword design, but Human Fred gets a foot sword alongside his hand sword for low-reaching and dual-wielding attacks - keep in mind that Human Fred, unlike the two alts I'm about to mention, doesn't even have any recolours of his own) Ansaksie and Atavist add an extra
limb to Asha that is fully animated. Simply adding an extra texture to toggle for human-Reptar's face would be nothing.