Suggestions for Arms PVP

Im fairly new to GSE and I’m having some trouble creating the right macro for me. I’m trying to create a simple one button macro for arms warrior PvP with maybe only rend as a separate key bind to my rotation. The only problem I run into is slam being used sometimes instead of mortal strike. A solution I found to this was this, “/castsequence Mortal Strike, Slam” however I’m not sure if later in the game this will continue to work due to higher rage regen. Is there another solution to this?