What do you think of my Warrior tank spec for my particular

My wife and a friend of ours are leveling together and planning on doing a lot of 3-man instancing. Our party consists of me (warrior tank), a Restoration druid, and a Mage (probably fire). Initially I was planning on going heavily in to Protection for the best possible tanking for our micro-group, but with our diminished DPS, and my minimal research, we've found it may be best if I lean more towards Arms. Here's the spec I came up with so far.
https://en.nostalrius.org/talents/warri ... 0530220050
We're currently nearing level 20, so it's still early in our leveling process. I'm planning on climbing the Arms tree first, then working my way through what I need in protection. What do you think? What suggestions do you have for my build?
Thanks!
https://en.nostalrius.org/talents/warri ... 0530220050
We're currently nearing level 20, so it's still early in our leveling process. I'm planning on climbing the Arms tree first, then working my way through what I need in protection. What do you think? What suggestions do you have for my build?
Thanks!