I do not agree that the final amount is determined by legal rights only. Settlements of claims alone add in variation to the letter of the law.
But put that aside. Both sides want to be in control of the money for as long as possible.
This is the reverse of the player agents who tried, successfully for a while, to get mega bonuses into the contracts of the early first round picks. Year by year they wore teams down and got the money for lower picks. Before the last CBA, they were close to the 10th pick of the round.