some times you have to use for each to get all the stuff in the SOL, sometimes you don't. I usually just use the for each statement to be sure, but perhaps that is wasting time. Perhaps a tutorial on when you don't need the for each would be good.
For example if a single sprite scedules a TIMER event for itself in the future if more than one sprite scedules that event you are going to have multiple sprites in the event not just one if they landed in the same tic.