I created the rotation based on the mix of Bajheera's PvP rotation and the best Arms PvE rotation for maximum DPS.
The 2 Overpowers should do the same amount of damage as one Slam, but as a side-effect Overpower reduces the cooldown left on Mortal Strike by 0.5 second. As I said earlier the CR is using Slam when Recklessness is up(because Slam benefits more from Recklessness than Overpower does) or when you're above 70 rage(to keep your rage for burst).
Do you still want to use Slam more?
Also, if you want to control your burst then you can turn it off by setting the "Pop burst CDs below target hp%" option to 0%. Then you can use your burst abilities for yourself. The CR will react to it and will use the burst rotation.