Actually, I think perhaps you misunderstand what training for the NT means. It's not a big deal, and he is your player. You can train him however you want to, and you have done an excellent job of training him to be a kickass Thai D.1 player. At this point he is a great player for our domestic league, but he cannot play in the NT except as a backup.
I will give you a rundown of what I think are the three most important skills for the NT by position. They should all be at least 15 to make the team competitive. Having strong secondaries is great, but at the NT level if the primary skills for each position are lacking, the team will get drilled every time.
PG- OD HA PA
SG- JS JR OD
SF-JS OD DR (with ID and REB at least 11)
PF- ID IS REB
C- ID REB SB
For guards, no skill should be lower than 6 and for big men no skill should be lower than 4 (JR and OD can be 4 for a C). If I could create a team, those would be the parameters.
Once I scored a basket that still makes me laugh.