I think you are over concerned about an MBA as having a value per se.
The other cases you mention are degrees related to a specific job wich requires same.
And my guess is at least some of the cases involve one went to school and the other went to work and helped pay for it.
Tax logic is not divorce logic.
I fail to see what an actuary has to do with it- The fact that you changed jobs and now earn 4,000 more probably has little to do with having an MBA---and as you put it the decided majority of peers in your firm do not hold an MBA--would be helpful to check if the recruting requirement or position description did not have some blurb like MBA highly desirable ...
If lets say the typical job change in your area is for 10% or 6000 then it would be very hard to say that in your case the MBA was the cause of your salary increase if most folks did as well if not better without one?
Is your STBX yapping off about the value of you MBA? Don't add fuel to the fire!
Sure, the folks who market MBA's like to focus on the value added --but a good amount of that is for marketing. A while back I crunched a few numbers on Americas 400 richest--turns out the folks w/o degrees were slightly richer than the folks with degrees!
Personally I think you unwise to not use legal counsel. Legal counsel should have a much better idea of whats likely to count in your state.
I'm not sure if an MBA having a discernable value to be divided under equitable distribution is any more rational than if spouse paid to enhance her career via cosmetic surgery or dental surgery ?