I might be wrong. But I think many are being too hard on Loomis. When Loomis hired Payton, it wasn't because he was the more experienced or most sought-after candidate. I thought there were better options. I believe he was a QB coach for Dallas, and he was demoted while with the Giants. But he was the one who "Wowed" Loomis the most even if he was maybe the most inexperienced.
I understand the DA hire because the thinking was that the fall-off in Payton's last year was injuries, etc. and that the train would stay on the tracks with DA. Now that that's clearly not the case, I don't think he changes from wanting to be "Wowed" rather than someone he knows. And if it is someone like AG, it will be because he gave the best interview, not because Loomis knows him.