Step X: Promote the best sales person to sales manager.

This is almost certain to ruin a sales force: promote the best sales person to sales manager. First, you just got rid of your best sales person. He can not sell anymore, he has to manage. And there is the second problem, this person can probably sell and probably has little skill in managing. So all the other sales people will start to leave. Third, the life blood of a top sales person is sales. Now you've taken away the raison d'etre of a terrific worker.

And finally, the top sales person is probably making great money (see step X) and the promotion to sales manager is probably a cut in pay. Sure talk to the top guy before hiring a new manager, but money will speak.