Wouldn't Stacey turn to Cappy and say, "Wells is ready." And Cappy goes, "cool, I'll start him." Isn't that how it works? Same with Ata.
They train together so Cappy will see how he is going there. Jones will have input as to how he is going during games as well. It wouldn't surprise me if the opinions of people like Ali and Robson are sought as well.
They will be trying to develop him so he can swim with the big fish because they want him to have the best chance to succeed.