Things to deal with CS that I don't see happening atm in this thread.
1) Having 2pc t14 (which most do) boosts Mortal Strike damage to 219%, 1% under Slam, and with it causing Enrage on Crits, for more damage/more rage to dump into damage, MS>Slam even during CS.
2) Slam>Overpower. 2 Slams>2 Overpowers. 1 Slam< 2 Overpowers. 2 Slams> 3 Overpower. Why? Because of the bonus crit, ontop of us already probably stacking crit giving the average Overpower to hit for 61% of a Slam hit, despite being much weaker.
3) With the above numbers in hand, you could go to say under normal conditions: CS->MS->Slam->Op->Op->MS(Slam if no t14.2pc or CS). However, since you'd be delaying a MS, thus less rage/Enrage/TfBs by slamming at the end without t14.2pc, I don't think it's worth it.
Refreshing CS seems to be a worthwhile alternative at the end.
EDIT: for the above rotation, you might have utilize the in-game Custom Lag Tolerance and overadjust it to queue your abilities as soon as gcd ends.
Why don't they make it so slam does 20% extra dmg (or cost less rage or something) when colossus smash is up?
Their intent is obviously to make us switch the position of slam and overpowerwhen colossus smash is up, which I think is actually pretty fun rotationally. While having a simple MS>OP>Slam rotation is fine...I like their intended rotation better.