As had been previously rumored, the Pistons are adding a pair of former NBA players to their coaching staff, announcing today that Keith Bogans and Rashard Lewis are coming aboard as player development assistants, writes Mike Curtis of The Detroit News. The Pistons have also hired former Celtics assistant Brandon Bailey as a player development assistant and Brittni Donaldson – formerly of the Raptors – as an assistant coach and director of coaching analytics. The team announced a series of other promotions, including George David to associate general manager and Rob Murphy, Josh Bartelstein, and Tony Leotti to assistant GM.…