Maul is off the GCD. You do not want to be spending finger-movement time on something off the GCD without also triggering a GCD ability. So:
#showtooltip Maul
/cast Maul
/cast Swipe
Put it next to Swipe. Then when you're spamming Swipe, you can throw in a Maul-enhanced Swipe any time you would otherwise become rage-capped, and there is no current value in spending rage on your damage-mitigation abilities.
(Tested on a target dummy. Maul and Swipe did in fact both land from a single keypress.)