The FI affects all levels of your franchise. He's most important for the defensive development of your younger prospects, the ones down in the lowest minor league levels who have the most potential for growth.
The impact of the ML BC for anything, beyond when the ML manager gets ejected from a game, is questionable at best. If he has any impact at all on ML players development, it would be as a small influence on top of the primary coaches for each discipline (hitting, pitching, fielding, base running).
2/3/2013 2:08 PM (edited)