Adams fell off a cliff last year because teams took away the passing lanes between him and Russ. Because Westbrook's favorite targets are big men (this has to do with when he passes the ball on drives), it resulted in Adams being in poor positions, and thus taking low quality shots.
With Paul George and Patrick Patterson, though, it will be much more difficult for teams to take away the passing lanes between Russ and Adams. For evidence, remember what happened two years ago with Durant and Ibaka, which allowed Adams to feast against basically everyone.
The Thunder are going to be a really good team this year. The problem is that they have guys like Enes Kanter and Kyle Singler who take up loads of cap space and cannot play against the best teams in the NBA.
Also, on this note, that Roberson contract was outstanding. RPM ranks him as the 58th best player in the league, which is mainly a testament to his defense, but also because he is not as terrible on offense as people assume. Sure, he's arguably the worst shooter in the league, but he understands where he should be on thee floor to allow Westbrook the greatest playmaking potential, is arguably the best wing screener in the NBA, and is a solid rebounder.
Also, if you think back to the KD-Thunder, Roberson and Ibaka switched roles on offense. So Roberson essentially played as a midrange 4 instead of as a wing. Given Patterson's solid 3pt shooting and playmaking ability, my bet is that this happens again, and Roberson's shooting will be far less of a problem.