Of course it's a fair point, someone else mentions they'll trust Pep, I'm making the point that he has very real doubts too. Much like blues are expressing here.
He did wish to bring in Ter Stegen, and only hasn't because he's decided to stay at Barca.
Ter Stegen would not move to be back up. He'd be number one.
Now Pep of course would've given Joe the chance to prove he could adapt to his side and demands, but I think had that moved happened the likelihood is that Ter Stegen would've become number 1.
Either way, Pep will bring in a new goalkeeper this summer and he'll be of a much greater quality than Caballero. He will compete with Joe to be number one.