The Hamlet Project

This play is very confusing to me. And when I say “this play” I mean The Mousetrap/The Murder of Gonzago/Whatever This Thing Is That the Danish Court Is Watching.
So – the main characters are Gonzago and Baptista, a married couple with Italian names in Vienna. (Already – huh?) They are a Duke and (presumably) a Duchess. Yet – the roles in the previous bit of this play are clearly a King and a Queen. Are the Duke and Duchess the same as the King and Queen?
It feels as if the language at the beginning is more ancient, more mythic, more in the Trojan wheelhouse of these players. Gonzago and Baptista suggest a more middle class story, a story about politics and money. It makes me think of Measure for Measure. That’s where Gonzago and Baptista belong, a play that also takes place in Vienna with some Italian names – and not with that arch language.
But then – Lucianus will enter. He is the nephew to the King. And his language is as arch and mythic as the openers. No mention of the Duke again. In this play are the Duke and King interchangeable? As a piece of plot, this courtly performance is very confusing. Or maybe it’s just Hamlet that’s confusing it. Taken without his explanations, it actually makes more sense.
Ophelia tells him he is as good as a chorus – but if so – he’s an obfuscating one – a chorus that seeks to confuse and muddle the plot.