Sorry but just how many times did MS race a car alien to him? Twice, when he was a pup?
Below is a list of cars MS drove, that were new/alien to him:
Jordan (1991) - his team-mate was de cesaris, whom he outscored during the 6 races he was with Jordan. The car was not designed around him and he outgunned his team-mate.
Bennetton (1992) - his team-mate was Martin Brundle who was actually very good. MS beat him though, in a car which was alien to him. The first race results were: 4th, 3rd, 3rd, 2nd. Brundle scored 38pts, MS scored 53pts.
Ferrari (1996) - MS finished 3rd in the championship, behind the all-conquering Williams, in a car which once again, was alien to him. He scored 59pts, while Irvine, his team-mate, scored 11pts. (Irvine had a lot of DNF's that season).
Mercedes (2010) - after 4 qualifying sessions, Rosberg leads the qualifying race 4-0, in a car, which is also alien to him. After 3 races, Rosberg leads MS by 35pts to 9pts.
Based on the first 3 races and 4 qualifying sessions, Rosberg is doing to MS, what MS used to do to his team-mates: dominate them.
In fact out of all the new team-mate combinations (Alonso-Massa, Button-Hamilton, Hulkenburg-Barrichello, etc), the biggest disparity seems to be between MS and Rosberg.