Even if you accept the premise that the 76ers benefited from trading Samuel Dalembert--Chris Mannix of Sports Illustrated says he was "poisoning [the] locker room"--it's hard to argue that the trade helps them on the court. Tom Ziller brings that fact to light in his breakdown of Dalembert's defense, as compared to Spencer Hawes', at Sactown Royalty.
Now, the big enchilada: post defense.
Post-up plays constituted 40 percent of Dalembert's defensive possessions, and 45 percent of Hawes'. Dalembert allowed opponents to score 0.87 points per possession. Hawes allowed 0.97 ppp. Dalembert fouled more frequently but forced almost twice as many turnovers, and held opponents to 43.7 percent shooting in the post vs. 48.4 percent for Hawes.
Once again, this is a massive defensive upgrade.
A defensive upgrade for the Kings and, by extension, a defensive downgrade for Philadelphia. Prior to the deal, the Sixers at least stood a chance at being a solid defensive team, with Andre Iguodala and Jrue Holiday locking down the perimeter and Dalembert doing work on the inside. Replacing Dalembert with the decidedly less stout Hawes complicates that task.