The idea is that like on the actual D-League, where the games practicaly does not interest anyone, so is this league.
Hence, there is no meaning of actualy playing.
It has nothing to do with GS management.
As I wrote on a specific week a player could not play on both leagues (or be sold).
In addition, it could be define that one more drawback will be that the GS when returning to the "real" league will be only (and always) "Average" (for example).
Regarding the Training issue you've brought;
Yes, it is (almost) exactly that.
In most cases, the drafted players are just does not worth the hustle of real-training at their team (again - exactly like in the NBA). But, the players are still may be observed as future prospect fot that team, but only if he could be trained.
This suggestion makes the draft a little bit more something that worth investing at. Especially at higher leagues.
Regarding a server issue who had been brought here (by someone else).
Are you realy sure you can tell how much will it cost in server time? I doubt that.
Are you realy sure that the BB-masters will not prefer adding this (or any other feature) that may be worth paying more for better servers? You don't and cannot know.
Any "Real" feature will cost in performance, should we close all this "Suggestions" forum? No we don't.