I think you need to look into what random actually means. You have more of a chance that legendary items will drop from enemies you kill than enemies you ignore obviously. Bumping the difficulty up to lvl 24+ has no effect on the loot you get at the end of the strike. As I said, marks and rep? You're better off doing patrols. The difference is when you're doing a patrol you're solo, not being an asshole and rushing a strike.