I think FFVI is unique for not only having a large cast of characters, but making them an important part of the story. As opposed to the dozens of people who join up with you in a game like Chrono Cross.
Well, not every game can work characters like Relm, Strago, Cyan, Gau, Mog, Umaro, Gogo, and Shadow into their complex narratives like Final Fantasy VI did! You can maybe argue that Shadow plays an important role in the story, if only as a dues ex machina, but if you honestly think that Relm, Strago, Cyan, Gau, Mog, Umaro and Gogo impact the story in any meaningful way... I don't know what to tell you.
Oh, and I'm totally not supporting Chrono Cross's cardboard standees with different accents or anything, although quite a few of them were pretty awesome. Mojo is one of the best things in an RPG, ever.