You said the Sunnis were more moderate. Actually, they aren't. Saudi Arabia(a Sunni country) is considerably worst than Iran(a Shiite) country on all sorts of human rights abuses and screwed up Sharia law crap. It is not even close. Al Queda, ISIS and all these factions are also Sunni. Hezbollah is a Shiite faction but from what I have seen, they mainly operate in Lebanon. There are plenty of bad guys on both sides, but Sunnis are not more moderate.