I agree with the ejection on Greenlaw. Violence in sports inherently comes with a hard boundary where that violence stops.
If you are a boxer or MMA fighter, you can hammer away on your opponent in the ring all day. But if you go after their trainers, that's going to get you a license suspension or criminal battery charges.
Even in football, there are limits on how and where you can hit players. Can't horse collar them, can't dive at their knees, etc. And if you hit a non-player like a referee or a medical trainer, like that idiot Quay Walker did, that's an ejection too. I don't see how a coach or staffer is different than a referee or medic. They are all unpadded and basically exist outside of the violence of the game.
But by the same turn, that staffer has to remain outside of the game as well. He has no business putting his hands on players, and he interferes with the game on the field by doing so. If Greenlaw hadn't put his hands in the security guy's face, I would have penalized Philly 15 yards for failure to control their sideline, and ejected that staffer. Then I'd talk with Goodell about whether a suspension from his job is warranted.