It's enough to have eyes to see that SNK makes several designs (sketchs) and designs (test sprites) for each game, and most of the time they add it to the mooks, ingame galleries or simply quietly "can them" and later speak about it as "guys that didn't make it". 99,9999999999% of the time nothing becomes of these guys; the only ones that kinda "came back to bite us" where I think Whip and Angel (though Angel is understandable, pretty much all of Styleos female sketches look like clones of her, but with less clothing).
If you have a PSX game plug it in and check the art galleries for yourself, you'll notice some of the sketches of the time there; they just mean nothing. Usually the reason for the designs to be canned is that they are too radical in fashion and simply don't fit in with the cast (qualification which all of the XII unused designs (which are way more than 3)) fulfill perfectly).
.... Speaking of, is funny how times change. Back in 95' they could release unused designs and storyline only characters and be cool with it (like that Rugal's male bishounen secretary)... Now the moment that they made guys like Botan to move over the storyline there is these intense fanwhine voice on how they didn't work hard enough to put them in or canned them because they didn't wanted to work more or that they are hidden within the game upon secret conditions or something.