Only 7? Boy, talk about under-rating him. He should be at least where Aaron Rodgers is, where the GB line literally dropped 10+ points once word got out AR wouldn't be playing in a game due to injury. They would have a hard time scoring 17 points a game without Brady. He is similar to what Steve Young was with the 49ers before the 49ers long decline: Brady continues to hide a lot of flaws NE has because he plays that well.
Brady might be an old guy, but only a few people know how to drive the NE offense as well as he does. Vegas obviously underestimates how hard it is to execute extremely specific timing patterns with a veteran QB..