Let's at least use the correct numbers then.
SoW: Increase Movement Speed by 34% (L9) to 55% (L50)
Selos: Increase Movement Speed by 20% (L5) to 65% (L50)
Selos, starts lower, and caps higher. The per level increase will always be higher per elementary math. With a drum, the two are incomparable.
It's obvious if Freez was out running you that you're like level 9 and he had a level 50 shaman sow him,.