This was against real basketball talent. Bertans, Goran Dragic, Porzingis, A. Randolph all on the floor for the game. This is better competition than anything in the NCAA or Summer League '17.
That's another thing people tend to forget.
Doncic will come to the NBA having played against FC Barcelona, Fenerbahce, Olympiakos, CSKA Moscow, Panathinaikos, Valencia, Milan, etc etc.
This is the best non-NBA competition and cannot be compared to NCAA or the Chinese League, to name a couple.