I agree with the thoughts on Mayo. You can be great with Xs and Os but if you can't get guys to buy in and want to play for you, it doesn't matter. Mayo's got the personality to be successful and I'd be willing to bet that like Flores, he would be if he also surrounded himself with the right people.
On Flores, I think I read something that the issue was he wanted more decisions to go through him instead of just being brought into the loop, which is apparently where the problem was. I forget the link so I'll have to dig it out, but I think that's what caused the conflict and led to him being let go.