hi! You might get something out of these posts. They don't address the question of "why do the Greeks claim Alexander", but rather the question of whether Alexander the Great was Greek, Macedonian, both, and what those terms mean when applied to the time Alexander lived

• Classicists, do you consider Alexander the Great to be a Greek, or a Macedonian- a nationality that should remain distinct from Greece?

• Did Alexander the Great really say that "whoever has been educated as a Greek is Greek"?

• Were the ancient Macedonians culturally and ethnically distinct from the Greeks, or were they a Greek society operating independently of the city-states in the south?

• How "Greek" was ancient Macedonia?