LogFAQs > #980126789

Fighters in Dragonball were already moving too fast for the naked eye to see, and able to blow up the moon with energy attacks. And those are just humans in the Dragon Universe. Goku as a child was beyond normal human perception in terms of speed, and far beyond the normal human in power. And Raditz completely eclipses him.

Omni-Man also isn't Supes levels of invulnerable - he's shown taking damage often enough from other characters, and his speed feats, etc. are nothing special. So your average Viltrumite is, compared to a Saiyan, not very fast... and while they're pretty strong and could deal some damage, it would be nowhere near enough to close the deal.

Saiyans stomp, and they stomp hard. The average Saiyan outclasses the top Viltrumite in terms of both speed and power. The Viltrumites may be a threat in Invincible, but most characters in Invincible aren't anything special. Viltrumites are, for example, FAR weaker than the Kryptonians they emulate.

Saiyans don't even need to bring Oozaru into the equation for the win.