Correct me if i'm wrong bro, my understanding on this draft is that Adams is the top pick and he is a regular in the roster come the opening of the season while Isaac Go can be used only if there are no activity on the Gilas team. If that is correct, i find it awkward on the teams and players as the one drafted for Gilas may not jell well with their mother teams as they are in and out of the team for national duties.
You are somehow correct that Adams can be used as a regular in the Columbian roster while in the case of Isaac Go, Columbian needs to wait for three long years before he became a regular to their team because Isaac Go along with four others have contract with SBP to play with Gilas. The wait won't be that long if Gilas decided to dropped them in the line-up.
Watch this video to learn more, this is not official though but you can have some ideas on how this is being done.
https://www.youtube.com/watch?v=LL8MzvtmFoQ