To further this argument I looked at the 5 man lineup stats for the Pelicans this season. The most common lineup was Rondo, Moore, Holiday, Davis, and Cousins. This lineup had a net rating of -2.9 and a defensive rating of 109. The second most common lineup was Mirotic as a replacement for Cousins. This lineup has a net rating of 16.8 and a defensive rating of 97.4.
Does this mean Mirotic has an extremely high impact on winning? Absolutely not. I would argue that he isn't a major asset or liability. The statistics and eyeball test indicate that Cousins' attitude and poor conditioning was dragging the rest of his teammates down. Cousins is like the anti-Horford. He puts together monster stat lines but doesn't make his teammates better, puts forth inconsistent effort, and routinely checks out of games.