"If it's not managed? I tell the Ringmaster and she manages it. Or I manage it myself."

Cole's certain the Ringmaster knows about Rhys and Jack. Why would she bring him on if she didn't know? But she has so much to do and so much to manage and so many people that he knows she can't keep an eye on everybody at the same time. Cole can help with that. Cole can keep Rhys's secret (because Rhys obviously wants it to be secret) while also keeping an eye on Rhys's behavior.

No comment on how he can manage it himself, though.