well, if you watch the games and rewatch them. You see Henne changing something at the LOS. doesnt mean he read anything real or what. He just may have changed something for the sake of changing something. Peyton Manning would often change at LOS and if you were paying attention at all, you would notice that about 75% of the time, it was changed to a run. He was changing something to show the defense he was changing something when in reality, he was not. Everyone on offense knew the playcall. It was a run. Manning was making it look like he was switching up to a diff pass route.
Often times, its not whether the Qb can read a defense or not but whether the WR sees the blitz coming and does a hot read to change without even audibilizing. Its an eye to eye thing.
They were doing this the other day in practice. Hot reads. Guess who the guy Henne was doing it with mostly? Not Marshall, but Gates and Hartline that one day. The WR who shows the smarts at picking it up with the QB will get the rock.
Marino -----> Duper Clayton. They were great at playing mindgames with CB's at LOS and reading blitzes. Alot of the times, they would just run there usual route cus Marino was so fast getting the ball out it didnt matter.