Agree 100% with Wunderkind
Haug has no part in designing the car or employing staff. His primary role in the team is that of PR and reporting back to mercedes on events on the ground.
As for the discreprancy in engines, I think that is unfounded speculation being touted mischievously by X.
No way would Mercedes-Benz take away an oppurtunity of victory to McLaren if it meant them being 0.2KMH quicker down the straight due to an engine that has a fraction more grunt.
McLaren are still Mercedes liveried and badged.