I came up with some more points to strengthen my argument. And now that the Denver/Chiefs game is over, I thought I would post it.
Number 1, defenses only started to have players with live helmets from 2008 and on wards. They have a tradition of using signals to call a defensive coverage. Offenses have had a player with a live helmet since 1994.
Number 2, It is easier for an offense to key in on what a defense is doing pre-snap. Most keys that a defense is looking for happen after the offense snaps the ball. However, an offense can decipher many things about a defense pre-snap. For example, sending a man in motion can give an indication about the coverage.
An offensive formation in a certain personnel grouping may give you an indication of what play an offense might run. But usually a good offense likes to break tendencies and has the ability to run many different plays from a certain formation and or personnel grouping. A defense with its own personnel groupings is not as flexible.
Number 3, the communication cutoff when the play clock is down to 15 is there for a specific reason. The league wants the Qb to fly solo for those crucial seconds before the snap. With Philadelphia's coaches having a good pre-snap read from the sideline and above in the box, and then changing the play with the use of signals, is simply ignoring the the spirit of the rule.
Not to mention my other point that I illustrated in my previous post. The offense controls when the ball is snapped, they can look to the sideline and not worry about the play starting. A defense does not have the same luxury. Looking to the sideline for a defensive play call, may lead the defense to be caught off guard and out of position.
That is all.
