By the way, I mentioned this earlier that this is likely a horizontal price fixing scheme which is a
per se (meaning "automatic") violation of the Sherman Act. An "unofficial agreement/order" to not exceed a cap is a horizontal price fixing scheme and is an actionable anti-competitive restraint on trade. A suit can be filed. And a "rule of reason" violation might also be actionable for the collusion involved in punishing the Cowboys and the Commanders.
As I mentioned earlier, I know just enough about antitrust law to be dangerous, though I am not expert in it. However, I am an expert in suing the crap out of companies though, and that is what I do for a living. And there certainly appears to be a good faith basis to file suit.
It wouldn't even take much work. Much of the legal issues have already been briefed: the thrust of Brady's 2010 lawsuit is that the salary cap is a horizontal price fixing scheme that violates antitrust laws. See:
http://bizoffootball.com/docs/03112011NFLPAAnti_Trust_Filing.pdf
You could crib from that and get something on file quickly.
Against filing two suit are two considerations: (1) Did Jerry agree to this punishment? That is still the unknown, and if he did, no suit. (2) Jerry loves the NFL and profits off it, does he want to tarnish the league by suing it? Probably not.
But he could do it. Sue the *******s.