Oh, well he is quite heavy. It is nice to have a driver with bigger level but that's not everything, far from it.
Look at
this driver, he have minimum weight and maximum stamina. I almost at the very bottom of my league in terms of my level and my car stats. But with that driver, I entered 5 races, got 5 poles, got 5 wins and got 5 fastest laps, with almost the worst car, and he is only talent 2 and level 6 now (was level 4 or 5 when I got him I think).