There are always Dimitri or Demetrios etc people where I live, all of them of Greek descent. And they all seem to end up going by Jimmy! Which I think is a courtesy to the rest of us, to whom the name is unfamiliar.
I once knew a South African Greek whose name is Apostolos; he chose to go by Albert. Same reason. (His brother is Peter, and that was no problem to anyone so he kept it unaltered.)