C`Tan are just 3, out of which one is a wuss, the other is sleeping and the third doesn`t scare the orks
The fourth doesn`t count because he`s not allowed to play in the galaxy.
The emperor is in clinical death since the heresy.
Chaos would have done something by now if they could.
The think that keeps the orks from taking over the galaxy is... well, their orkiness
Orks and humans have a lot in common, we both fight among arouselves until some big guy kicks our heads in and puts us in line and sends us to kill the rest of the galaxy
That`s why the emperor is out of the picture, if he were active, the galaxy would be ours
and that would leave room for any serooius enemies or interesting plots now, would it