A massive endeavor it would be, due to many factors - including affiliate changes from year to year, wildly varying levels of minors from one year to the next and from team to team, independent teams/leagues, etc.
There's a great discussion on this subject here -
http://www.ootpdevelopments.com/boar...r-leagues.html - including the challenges and some possible solutions. I'll shamelessly point out that I think the best solution is in the last post of the thread (yes, mine
), which lays out that everything could be controlled by csv files. This would put the onus on Markus to only allow for the csv files to control the setup, structure, and changes of minors. He would not have to decide what's reasonably-close to authentic or actual; that would be up to modders, etc.
I'll admit that this doesn't address the "minors' financials' part of your request.