I have a friend who gets weird ideas all the time. either they are "strokes of genius" or just plain "strokes". in my opinion, this slann is a stroke. I like the creativity, but i think that the extra floor added is wrong for fluff reasons (who would dare sit higher than the mighty slann!?) and also for aesthetic reasons, since it destroys the balance of the model.
I like the salamander much better, even if it is very unrealistic (it doenst have to be realistic in warhammer FANTASY battles), but i think it is a mistake to try the same idea with a slann.
Naturally, you shouldnt value what i say more than what you think, but you asked for comments and that is mine.