Partial Source: Pwinsider
Dutch Mantel being added to Jack Swagger's character as Zeb Colter was done to help Jack Swagger get over and connect with audiences. While Vince McMahon felt managers were an "antiquated" idea for the business, there has been talk on and off last year of bringing them back full time.
Mantel and Jim Mitchell's names were mentioned last year in creative discussions. There could be more names brought in to get new talent over, but this is not confirmed.