It's hard to keep track of what I'm talking about at any particular moment. I started off wonderin why T/V, which was, as you suggest, wondering why foreign paradigms were being used in an English context. Then I shifted to wondering whether Latin had this same sort of pronomial hijinks for purposes of sucking up to one's betters. How different modern languages handle this is a whole nother question. I'm sure Japanese would have a veritable treasure trove of funnies along these lines, but how many of them would be pronomial I wouldn't care to guess.