Phronesis and éxypnos are Greek words for intelligence. What makes you think that Aris is Greek for intelligence? I agree with you that Aris probably does not have the same root as Ares as this site maintains. It could be that Aris comes from αριστος (aristos) "best."
Actually, Aris is the common transliteration of the Modern Greek pronunciation of Ares. The Greek spelling is the same, but it's transliterated differently in Roman characters because Modern Greek is not the same as Ancient Greek.