I've been active on the forums since around season 23. You give some very good insight on various topics and generally I view you as a very credible source when it comes to BB information. With that being said, I think this conversation has gotten out of handed I don't agree with you on this one.
Mono-skilled players don't mean subpar training when it comes to U21 NT. I won four gold medals for the USA U21 NT from seasons 26-29 and the training process looks entirely different for U21 than it does for NT or even a regular team on BB. The USA has also had numerous players throughout my tenure who were basically only trained in primary skills and still went on to play games for our NT down the line.
Murray/Harris/MPJ/Grant/Jokic - 2020 NBA Champs