Why would you compare the outfits of a ninja/assassin to a UFC fighter?  It's like you you have completely missed the point of a costume design and are proving that your only real concern is that you want to see a skimpy woman.  Scorpion, Sub, and Noob (also ninja/assassins) don't have UFC style costumes.  Why aren't you throwing a fit that the male ninjas aren't dressed like a UFC fighter?  Is it because with males character archtype matters, but with females we should ignore archtype and put priority on having Sonya wear a thong again?
Young Johnny, a martial artist has topless costumes, but old Johnny, a military-lite character does not, same with Jax.
Shao Kahn and Baraka are warlord type characters and have outfits showing lots of skin.  Sheeva is a warlord type character and also shows lots of skin, but that doesn't count because the Half Dragon lady looks too manly?