This is quite correct, only that in ancient greek, the letters eta and omega where, as they called it, makrochrona or long-term. So when a word contains an eta (η) or an omega (ω), they would pronounce the word with more emphasis. Rome, in ancient greek, would be pronounced for instance like Roomee.

Also, I've been making some thought about the name, ''Arche Megales Hellados''. By that prospective, wouldn't Arche Seleukeia be ''Arche Seleukeias''? You see, Megales Hellados (tes) is the genike form, while Seleukeia not. Seleukeias would be, according to keravnos' correction, the right form.