It's a bit simplistic to only look at it in one year figures, he still has 4 years to go and that's $4m that the Cowboys have to spend on him. If they were to go, say, 50/50 then that would release $2m for them, that's a more realistic view of what they have to gain. If it was, say, 25/75 then they save $3m over the 4 years.
Maybe the answer is they release him now pay the whole of his $1m in 2024, and then someone else picks up the $3m. Which really means he cost $750 a year for the 4 years that someone else has him.
He might give them $750k in value this year, then $550k in 2025, $350k in 2026 and not much in 2027. That's $1,050k they get in value over the 4 years when they will be paying $4m. Many ways to roll that dice.
Always a Bulldog