MGS's cover system was nothing like Gears of War's. In MGS you could slowly scale across walls if you kept the button pressed down and couldn't switch cover at all on the fly.I can't comment on the other games mentioned because I haven't played them, but I can assure you MGS was in no way a real inspiration for GOW's cover system.
Also the over the shoulder view was popularized by Resident Evil 4, not Gears of War. In fact I believe that Blezinski fella from Epic actually stated in an interview that they didn't know which direction to take the game until they saw RE4 in action and said they had to have it look like that. They were also considering first person shooter for the title.
Tag: Became a freaking mod and a complete douche, coincidentally, at the same time.
