I think you could say there are structually fast arts,ie wing chun perhaps,or maybe compare wado to shotokan?,so perhaps a fast person in a slower art may only be as quick as a slow person using a fast art!
There are arts that rely MORE on speed than power and vice versa, but all of them (Judo and Shotokan included) will emphasize speed as well.
Straight line vs circular motion. Ving Tsun vs Kenpo. Physics and body kinetics answers this question.