The thing that needs to be evaluated is this , Is his talent so good that its worth putting in so much resources and time into getting him to the required level which wont happen in 1 off season and will likely require 3 to see if he will ever be upto speed and does he have the will power to continue, I hope so but think he doe not !
For a team like Richmond to go this route and continue with Stack he needs to be so talented that you would need to be significantly better than players like Castagna ,Butler,Higgins,Graham etc - I dont believe this will happen
Maybe its better to put resources into a player like Podhajski,Fletcher,Lewis