I do not have much faith that DG will be able to carve out any sort of NBA career. I think he would be VERY successful in Europe, but he may very well end up wasting his best years in the U.S. chasing a dream.
I just don’t think he can guard a soul. If I were him, and I got drafted in the 2nd round with no guaranteed contract, I would go play overseas. Of course his draft rights would be held by someone, but if he crushes it in Europe and proves he belongs in the league, he can parlay that into a guaranteed contract.