You are a guy swinging an axe....not a ninja mage pirate space wizzard. Arms is about putting in your damage during colossus smash window and balancing your rage. Yea the rotation is not complex but there is not a lot of room for error if you want to min max. It is not a complex rotation but i don't want to say it is boring. A straight forward rotation that most people can be OK at with few skill-cap nuances shaping up to be a great spec. I wanted to play fury in Legion on warrior but to me arms seems more interesting vs Fury's BAMBAM. Fury is button mashing all the time and Arms is like percision strikes for powerful damage in small window.
Spec seems pretty good to me