I am sure there is plenty about this situation that will remain private, as it should be. I am not quite certain what "fit for the system" means - there has been some talk about what type of system Coach KY wants to implement (we usually are talking about offense here), and the discussion has been around an NBA-style, 5-out, ball movement offense, with significant pick-and-roll elements.
However, I also heard Blaine Fowler talk and others talk about how Coach Young's experience has meant adapting the offensive approach to fit the talents of the available players he is working with. So, in my mind, I would think that you can adjust the offensive approach a bit if needed to work with your available personnel and their talents, and the player can also develop if they are a D-1 level basketball athlete (example of Waterman). But, also, there might just be skills they need to have (shooting from range) from the beginning that Coach Young prefers to emphasize.
Will be interesting to see, for sure.