The Roman Reigns/Paul Heyman pairing will play out differently than what they did with Heyman and Brock Lesnar.
Dave Meltzer reported in this week's Wrestling Observer Newsletter that the idea is that since everyone knew that Lesnar was everyone's mercenary and was also friends with Heyman, WWE wants fans to know that there is no friendship between Reigns and Heyman. So basically, you won't see Reigns smiling during Heyman's promos or laughing at his jokes.
The idea for their storyline is that it is Reigns who is completely in charge of their business relationship and the story is that Heyman was done in wrestling without Lesnar around so he had nothing left and Reigns was the one who made the call to bring him back. Also, Heyman is supposed to be indebted to Reigns for saving his career.
Heyman has made it clear during his promos that he is the "Special Counsel to the Tribal Chief" so the "Advocate" title has been dropped for this relationship.
In regards to Reigns, WrestlingNews.co was told that the idea for his return was to give him an "edge" with the idea being that fans would cheer him since he's a heel and eventually he would turn into a babyface.