what do you have sort out about your strengths? you are already good at that.
it is improving your weaknesses that will make you a better player.
do you allow a player who works hard forward of the ball but is lazy as poo when the opposition have possession to continue to do so and just keep encouraging him to work hard forward and ignore his unwillingness to work back?
do you allow a ruckman who is a great tap ruckman but just stands there watching once the ball hits the ground and doesn't take a mark around the ground to continue on that way and only concentrate on what he already good at?
You are looking at it incorrectly. If you are lazy, chances are you're always going to be lazy. If you can't take a mark when you are recruited, chances are you're never going to be a good mark.
The best example is kicking. If you can't kick at 17 you're not going to be an elite kick ever.
What you are talking about is development through childhood and adolescence. I'm talking about players past that point. Hopefully you recruit players that don't have major deficiencies. Their strengths though are what attracted you to them and do if you can hoan them you create weapons. You build a team that has many different weapons.
The best example is if you're a poor shot for goal. What's the point of trying to make someone a great shot for goal as you'll almost certainly fail. If they are a reasonable field kick and a great mark, play them in the backline. Utilize their strengths. There's no point wasting your time on things that should have been worked on years ago.
Also I think we are also talking about PLAYING to ones strengths compared to DEVELOPING ones strengths or weaknesses. Sure you should try to improve areas of your game that are weaker but you should use your strengths during a game. What's the point of trying to use your weaknesses more than your strengths?