The problem is that the size of each base and fleet numbers in each base is subject to change, and historically has often changed. Because there are so many factors not involving envoy (like for one example the performance of other regionals flying for AA) that make AA shuffle flying around, it is impossible to predict. Even management doesn't always know very far in advance. The best you could do is tabulate which bases are flowing Captains when, which would involve a lot of work and would still produce uncertain results.