Of course, that requires putting down a definition of “ability to pay”… and it would not be surprising if the ex-spouses each tried to manipulate their finances to make their “ability to pay” appear smaller.
Again, OP needs a good divorce lawyer to help negotiate these things.
Is hiring a divorced lawyer potentially better in that s/he may be more familiar with divorce issues from a personal standpoint? If so, maybe even better if s/he helped pay for a kid’s college after divorce.