I am not sure there is a model for a coach, because everyone is different. I don't think you can pin-point a model for the successful approach, but I have my idea about some of their needed credentials. It is most important that you can relate to the kids coming into the program. Make no mistake about it, they may be bigger, faster, and stronger than the coach, but they are still kids who are not mature. When raising a child, that child understands discipline from his parents as long as that child knows their parents love him/her. You cannot discipline a child with good results unless you truly love him and want the best for him. It cannot be a selfish thing where you just want him to behave, yet you ignore him and withhold love from him.
I consider a coach as an extended parent who should want the best for his players while teaching them discipline and the game of football. I think a good coach also must be above reproach in his honesty with his players. He should not play favorites, and he must have empathy for all his players. I think the successful coach plays as many players as possible during the games to reward their hard work during the season. I also think playing as many as possible builds teamwork among all. The more that plays, the more they feel like part of the team, and even the starters begin to understand and accept that philosophy.
I don't think a coach necessarily has to have played the game, although it helps. Some of the most successful coaches were players that rarely saw the field, but gained a lot of football wisdom watching the game from the bench. In fact, if a person is not an exceptional athlete, he learns the finesse needed to excell and that carries over into coaching. I think a good coach needs to be smart, a good analizer of the game and able to adapt during the heat of a battle and during the entire season. A coach who relies on one system will soon be obsolete as the game changes over time and even sometimes during a game. He must be proactive and ready to change to gain an advantage.
I do not like a coach who tries to play it safe. I think a good coach must teach his players to be aggressive in all aspects of the game and never wait for the game to come to them. I think this true on both offense and defense. The worst defense ever in football is the bend-but-don't-break system. He should teach his team to never let down or relax in a game when they are ahead. It is foolish for a coach to tell his substitutes to hold down the score. The subs should always do their best and try to score on offense even if the team is leading 222-0. The same should be true on defense. Also, I have seen this many times over the years: the team scores a TD, and then relaxes on the kickoff and the other team runs it back for a TD or scores on their drive. Both offense and defense should be attacking and aggressive the entire game. If they get tired, send in the reserves, never relax.
The coach is the reason for success, not the players. A great coach with average players will beat a team with great players and an average coach. A great coach will beat you with his team or beat his team with your team. It all starts with the coach. A great coach will win regardless, but he will soon start attracting the great players and become almost unbeatable. If a team has weaknessed, it is the fault of the coach. A team is a mirror of its coach. If they have a lot of penalties, it is the fault of the coach. If they fumble a lot, it is the fault of the coach. If they do not intercept a lot of passes, it is still the fault of the coach for playing the wrong defense. If a team tackles poorly, it is the fault of the coach, etal. The buck always stops at the coach. If he wants better players, he can get them if they see he is a winner.
Actually, there are so many books and information everywhere, that it is possible for a person to have never played the game and still be a good coach. He would have knowledge of all aspects of the game from book learning, and he could act like a CEO as suggested, hire the right assistants and still be a good coach. Of course, there are many more angles to this, but the main thing stressed here is the coach is the catalyst for winning or losing.