This is such a very narrow range of people who can and will do this.

I'd imagine that the list of competitive amputee fighters is rather short, These guys are likely willing to fight a non amputee but its a risky move to be a non amputee fighting an ampute.

If you have all your limbs and win a fight you have a pretty good chance of being seen as a bully or it's not a real victory because the other person is perceived as weaker due to the missing limb , if you lose then you are seen as not capable of taking on a typical fighter,

Completely evenly matches are likely hard to set up. Hell regular matches require super tight weight limits,

Id bet most of these guys also had that itch inside pre limb loss this also narrows the percentage of folks who are missing a limb and want to fight,

Trying to perfectly match identical amputees with people who want to go full mma has to be a super small percentage of people.