If you put an average NBA offense — last season’s Detroit Pistons, for example — up against an elite European team’s offense, the Pistons would come out on top.
But the reason is talent not system (with all due respect to Stan Van Gundy). Those European teams don’t have anyone like Andre Drummond, a dynamic pick-and-roll point guard like Reggie Jackson, athletic wings like Kentavious Caldwell-Pope and Tobias Harris. European teams have good players, but not the same level of depth and athleticism.
They make up for it by a commitment to a ball-and-player movement rarely seen in the NBA.
Russell Westbrook talked about that after the Thunder’s recent game overseas.
The best NBA teams in recent years do both. The best example over the past few years was the last championship Spurs team, which was loaded with talent (Kawhi Leonard, Tony Parker, Tim Duncan, etc.) but played beautiful system basketball. That team may have had the highest level of execution the NBA has ever seen. The title teams from the Heat and Warriors did it as well (although not as much as those Spurs, in my opinion).
But far too many NBA teams just lean on that talent.