Oh huh, interesting and makes sense.

Very true. Also wasn't Greek pretty much the universal language of the time for writing? Like didn't even the Romans write in Greek a lot too?

Their existence makes sense given historical context. Egypt, particularly Alexandria, was mutli-cultural as hell eventually, with people from all over the region being in it. Lots of trade, so putting these stones out is the modern day equivalent of cities that get a lot of international travelers having signs in multiple languages.