Well sure but you don't need Zona Seeker or Golem either. I think everything we've listed as a travesty is optional.
(Coliseum.)
I'm actually making a concerted effort to use characters on this playthrough who I generally don't use. Floating Continent was a pretty different experience with Locke, Strago, and Relm (and Shadow); had to play a lot more defensively.
Anyway, despite my being much more likely to use a Gold Hairpin than Mog, I still always save Mog and run him around a bit. Partly because you can only grab the Water dance in the WoB (though that's no longer true in FF6A; the fight with Leviathan gives you one last shot at it).
And, y'know, if you're going to fill up your final parties, you have to have at least ONE of Mog, Umaro, or Gau. That's just math.
(Specifically, the pigeonhole principle! I remember that from college!)