The Rockets could have done everything you mentioned anyway. So the comparison is straight up Capela to Maker. Onuaku was a bad pick... among a ton of bad pick options, imo. I guess Patrick McCaw should have been the pick... i guess. But even the best scouts aren't going to hit in the 2nd round year after year.
This is where the one and done rule hurts the teams. It helps the players get to their 2nd contract to make big money, but teams whiff on picks more and more because of the small sample size scouting them.