At level 86 you won’t be experiencing the same gameplay as a 120 would, so none of this will apply until you’re max level.
First thing I would recommend is not using the method guides. They are no where near as kept up to date as the warrior community guides on icyveins and wowhead as they’re both maintained by a very active and well-versed theorycrafter in Skyhold, Archi.
Secondly the rotation you’ve described isn’t correct. First you should be opening with lucid + charge, CS and then MS, with MS being used off cooldown EXCEPT in the execute phase.
You have three options with the most popular is running fervor of battle (FoB) which will replace slam in your rotation with whirlwind (there is an exception to this, but I won’t go into that as it’s more advanced) which will be your primary rage dump outside of execute.
Or if you’re not using FoB, you’ll either be specced into rend or massacre. Rend is self explanatory, you keep the bleed up 100% on your main target and spread it in 2-3 target scenarios with SS or swapping. Four or higher your only priority is to keep it on the MT since you won’t have enough GCDs or rage to maintain it on so many targets.
Massacre is favoured on short fights (less than 5 minutes) as this will line up with your second or third lucid window during the execute phase or in fights with multiple execute phases (ilgyonoth), with rend being used in pure ST or short windows of target swapping. If you’re in a scenario where rend isn’t being used effectively (hectic add spawns e.g. vexiona, carapace, hivemind etc) it’s not worth using rend.
Lastly, arms is dependent on two things - lucid major and 3x Test of Might traits. These are not negotiable if you intend to plays arms. Test of Might will mean at the end of your colossus smash window, all your rage spent will be converted into strength. You’ll pool your rage just before CS is up (60 is good) and then proceed to spend it all (with priority still going to MS outside of execute.) After CS expires, you’ll have a large strength buff and continue your rotation as normal.
Lucid is vital for ToM as it will increase your rage gen by 100%, meaning that you’ll be gaining huge amounts of rage and as a result, a huge ToM stack.
This is a very simplified version of the arms rotation and I would again heavily emphasise using the guides I suggested at the top as they go into far more detail.