I think they know what they're doing and, I also think it's possible they may do something like, hand over the actual coaching reins from Vitt to somebody else in one of these preseason games, for part or all of the game, and NOT TELL ANYBODY they are doing it until after. Remember when Carmichael started calling the plays and being the voice in Drew's headset, they actually kinda didn't tell anybody until after the switch had already happened.

We don't let any information out before it's time!
Coach Payton learned well from the Tuna........

And so has Loomis and the Saints organization.
I find the Saints to be a well oiled machine, where before Payton's arrival that was not the case.