We'll worry about hypotheticals when they become actualities. As far as I can tell, we have two choices. Disguises don't count as the character being impersonated, or we continue to count disguises as the person being impersonated. Once we decide to only count the disguises that we as a community (in a manner to be determined... how?) think are sufficiently believable, the whole thread is in the crapper.
This standard would also apply to illusions. Does the prison illusion of Belkar count as an appearance for Belkar, even though it uses dialogue Belkar would never say? (We did count it, by the way.) What if the illusion were slightly less believable (yet still believed by the guards)? What if the illusory Belkar had a Hannibal Lecter like mask so you couldn't see his face, but was still Small size, and still used stilted dialogue Belkar wouldn't say?
Once we open this up to subjective interpretation, it's a nightmare.