Summer league is trash, it is always trash. It is hard to draw anything from any of it. The only guys who get a real chance to do anything are the guards, and it is only because they completely dominate the ball, usually using the opportunity to chuck up horrendous shots and wildly stupid running layups.
It might be useful to teams to evaluate players attitude and hustle but man... the basketball is freaking awful. And it shouldn't be a surprise, these games are played by guys who don't know eachother, got like 2 practices in before playing together and 95% of them will never see a meaningful NBA minute.