Michael had to removed because Walt was, like Hurley gifted with some power that could overthrow the order of things (title of a Latin poem by Lucretius). In the same way, Sayid was correct to kill young Ben. Ulysses ordered that the son of Hector be tossed off the walls of Troy to prevent another war (see Euripides THE TROJAN WOMEN). Jack passed that test by making the right decision. Sayid is the cold killer. He is a good example for Jack. Sawyer was right to kill Cooper. Jack has to kill without hesitation. He is to face the ultimate evil. Of mice and men: the title comes from Robert Burns the best laid plans of mice and men sometimes gang aglee (go wrong). That's what happened to Jacob.