-akis, -akos, -opoulos, -oglou, mean the same thing. "son of" (women did not count those days); like "Mac"-Donald for Scotish, or "Fitz"-Patrick for Irish, etc.
The ending -akis has very little to do with Crete origin. There were NO or very few Cretan names Pre 1800 ending in -AKIS. Today, there are many Cretans with names ending in -akis but the majority of them are refugees from other parts of Greece or orphans. There are as many families with names ending in -akis in Chios then there are in Crete. etc etc etc.