We stomped on their corpses, burnt the shit out of them, and we will continue to burn the shit out of them... till the last Sunni dog alive on the Earth!"

We really have no numbers, but Iran, backed by their dogs the Hezbollah who were very brave when raping and killing unarmed Syrian Sunnis - probably slaughter well over 100,000 Sunnis.

Did they all hate each other before the civil war in Syria broke out? Yes, but now they have even more recent reasons to hate.