it is interesting to note, and i believe i have my years right, that Schumi won his first championship the same year that Senna was killed in Spain. i still think Schumacher would have surpassed all for wins and championships, but i don't know if Senna had been alive that he would have had the success he had, especially early in his career.
Senna's impact on the sport unfortunately did not come until after his passing. it allowed F1 to look at their cars from more of a safety issue. had Senna not passed, i don't think F1 would have made some of the safety innovations they did.
both were tremendous world champions and certainly left their marks on the sport, but from a pure numbers perspective, Schumacher is really in a class all by himself.
we had the discussion on here in the past that the only real name worth mentioning in the same breath as Schumacher is that of one Mario Andretti.