a hurry up offense with their defense is a recipe for disaster...not to mention their o-line and issues in the running game. Also, Jordan Cameron is terrible so not having a reliable pass catching tight end is another knock on it.
They don't have the personnel for it.
Honestly, the stuff coming from Gase is either a huge smokescreen or he thinks because it works in practice against his potentially historically bad secondary that it will work in games against other teams.