I shoot with a marine who served in Iraq. The training that they received was for the marine on point to have his rifle on "fire" and the others behind him to have it on "safe". Once they moved into a building, if a soldier's rifle moved to his shoulder, he flicked the safety off in the process. Also, if they were stacked up to clear a room inside, again only the first soldier would have his rifle on fire before entering. The first three soldiers stacked up would clear the room, but only the point man would already have his rifle on fire upon entering.
I agree that coming off safe as rifle comes to the shoulder seems very intuative. In the movie ( yes i get it's a movie ) the seals are " shouldered " as they search so you don't have that tactile que of mounting the rifle to sweep the safety. Not something that will affect me at all but always interesting to discover how tactics evolve and what works as a viable balance of safety/speed. Thanks to everyone for their thoughts, much appreciated