I understand the OP is trying to be sarcastic but i could think of a few:
The BIGGEST is that he's coming from a previous culture that understands how to WIN for a long time.
Charlie Weis (NCAA) : 41-49, one bowl win (Hawaii Bowl)
Romeo Crennel: 28-55, zero playoff appearances
Josh McDaniels: 11-17, zero playoff appearances
Bill O'Brien (Texans): 42-38, 1-3 playoff record
Matt Patricia: 6-10, zero playoff appearances
Eric Mangini: 33-47, 0-1 playoff record
There are six coaches who got head coaching jobs coming out of that 'winning culture' in New England.
Combined record: 161-216 in the regular season (.438) and 1-4 in the playoffs. If you pare it down to just the guys who went directly from the Patriots to an NFL head coaching job, the record sinks to 78-129 (.376).
Brian Flores coming from the New England Patriots is one of the worst arguments you can make as far as projecting success for him in the NFL.