Again, experience is important, but in the end experience does not guarantee you the ability to lead...to command a room...to have players want to play hard for you and believe in your system.
sigh........OK, one last try. Shanahan and Jackson have both successfully (you can decide if successful is correct to describe Jackson's tenure in Oakland) run a team. In doing so, I believe they have proven they can lead, command a room and have their players play hard for them. So in my little mind, both these guys have proven they can do it.
Any of the coordinators that are candidates and haven't been a head coach before haven't proven anything at all. You are assuming they bring that to the table....but you haven't given a single reason why you think they bring that to the table other than they are young. The experienced guys have proven they can do it through their actions. The younger guys???