Wizard of [ɑz]

I caught the tail end of the "Wizard of Oz" the other night, and was struck, naturally, by the way the actors talked. Isn't that the point of the movie? Among four main characters there are three distinct styles of pronunciation - all of them rather stagey, but interesting nevertheless. Dorothy, I think, is meant to sound fairly generic. Unlike the other Kansas characters she has no Midlands twang, though her speech is rhotic to the point of exaggeration, that is, she doesn't drop "r"s after vowels. In fact she is the only main character who is rhotic - the Scarecrow and Tin Woodman have what strikes me as an old-fashioned kind of formal American English which affects a pseudo-British "r" dropping, though both actors are from derhoticizing Boston, which could explain it. Bert Lahr, the actor who played the Cowardly Lion, is from New York, and his character, fittingly, has an exaggerated New York accent. Indeed, it seems possible that the Cowardly Lion's lines were written to be delivered in such an accent; why else would his aria, as it were, feature so prominently the word nerve - "noive," and others that rhyme with it. The Cowardly Lion also has a grammatical feature that crops up twice that absolutely floored me - Seeing the witch he says, "Who's her? Who's her?" Then later, seeing the Winkies, he says "Who's them? Who's them?" I've never heard anything like this, but I wonder if it used to be a feature of New York English, and maybe other vernaculars as well. Case is tricky in English; like any speaker of real English I use oblique pronouns in situations where high school English teachers say you shouldn't, but not in this case.