Movespeed gaps

I'm not sure how intentional this, but some champions are just naturally faster with less move speed. Today I played a match (3v3) in which I had 30+ move speed on an Alistar, who proceeded to outrun me. I then ran with a Sivir who ulted me and he continued to outrun me. I know there might be a difference with champions strides, but making up for 30-40 moves peed is a bit excessive.