First of all they weren't rangers. They were SFOD-D operator along with the British SBS. They were straight up denied of every way to kill OBL. For example Dalton Fury wanted to come up from the mountains of Pakistan to get a drop upon Osama where he would least expect them to, Delta also wanted to drop land mines, but again denied. At the end Osama was egressing into Pakistan Dalton Fury wanted to use 300 army rangers to block his escape route, but that was denied also. Army Bureaucracy at its finest.
Also, we shouldn't have trusted those rag-tag Afghan militia that set up a bogus ceasefire with Al-Qaeda. They should of been wiped out afterwards for collaborating with Al-Qaeda.