Far cry from you saying he made them worse. He had a drop in efficiency but not in wins. He was back in the finals and took 2 games off the Warriors without Kyrie and Love. The Heat didn't make the playoffs. I agree that they were all helping each other but it seems like they needed him more than he needed them.
He did make them worse. Their volume decreased. And given the fact they all saw a 7% drop in efficiency the following year it proves he didn't help them be more efficient anymore than they helped him.