I like what you are trying to do here, in making the societies different from each other and the real world. But the choice of terms might be a problem with other contexts in the readers minds. Just something to think about.
Like Hideoshi, I am late (in my case, very late) to the party, but something that w. bogart said earlier gave me an idea: This reminded me of the time when Samuel Johnson and James Boswell were travelling around England. IIRC, Johnson was writing his famous dictionary (published 1755). His wasn't the first, but it was the first to quote extensively in order to demonstrate the meanings of words. He quickly came into difficulties when he realised that different areas of England had different words for the same concept. People in Cornwall, in particular, were using their own language, which annoyed Johnson to no end. (If I recall, an elderly Cornishwoman tried to sell him some eggys, which he ranted about and told her they were called eggs). Hair-splitting as that may seem, this was nothing compared to what he ran into in Scotland ... but that's another story. His dictionary did record many weird and wonderful words, such as backfriend: "A friend backwards, an enemy in secret". Or nidorosity: "Eructation with the taste of undigested meat" (i.e. a really meaty burp). More here: 17 hilarious definitions from Johnson's dictionary. Perhaps these will give you some ideas for the differences (and even miscommunication) between the two clans. I can just imagine the conversation: "Good morrow to you, kind sir. I come unto your village seeking friendly conversation and company. Let us commence our discourse interfrastically." "What the hell's you talkin 'bout, chump?" ... except maybe not quite like that. P.S. I love the blunt way Johnson defines some of the words ... for instance, bum: "the part on which we sit." I'll give him alpha-plus for correctness but zero out of ten for energy or enthusiasm ...
