All the material said in promos by Zeb Colter mostly come from Colter himself (aka Dutch Mantell) according to a report by Dave Meltzer. Colter does have to get approval on what he can or cannot say, but he is allowed to come up with most of his own stuff for promos. It is said that at last weekend’s house shows that Colter and Jack Swagger got more heat for their material than anywhere else since they started last month. 

Source: The Wrestling Observer Newsletter