Control rate of manager sackings via database

[Supermercado99]

For instance, if I create a league system that goes down to the amateur ranks, I don't want the chairmen to be ruthlessly dismissing managers every six months. Idea is to have a setting for each division that biases rate of sacking. This would also help adjust realism between countries where managers are traditionally safer/in more danger. Could also have settings for how often managers just randomly up and walk out of a club for personal reasons - this would be especially helpful in the lower leagues.

Have tried doing this manually via supporter profiles (lowered expectations/raised patience), and low 'starting media expectations' but no avail.