First of all, Castle is a guard who a) isn't a lead ball handler, b) doesn't create an advantage when he does have the ball, c) turns down open shots to try to drive the ball into traffic, d) isn't going to be bigger or more athletic than other guys he's on the floor with. He defends and he's a ball mover, but he doesn't even have role on a competitive NBA team right now other than as a defensive backup 2/3. If that's the type of player you want to develop with the hope that he becomes a smaller version of Jimmy Butler one day, then go ahead. That outcome probably has about a 10% chance, and a player like that isn't a top-5 pick in this or any draft.
With Cody Williams, earlier in the season he was Colorado's lead ball handler. He could self-create and beat multiple defenders, scoring from different angles in a variety of situations. He led his team in scoring in several games. He has an elite finish percentage at the rim. He took and made open 3s at an efficient clip. His length and mobility gave him defensive presence guarding 1 - 3. He's got the right combination of a NBA tools, NBA skillset and position in the league. He injured his ankle mid-way during the season and was just starting to regain his confidence when CU's season ended.
Once the smoke clears and teams go through their pre-draft process, Williams is very likely to end up in the top 5 or 6 on a lot of teams' draft boards.
