You can always use your own key, and make your own groups, you know that, right?
Warriors have plenty of utility for m+. The damage you lose from taking shockwave is so small that it honestly doesn’t matter, and if you’re not taking shockwave for m+… well, maybe there’s a reason why it takes so long to get a group.
You’ve got Shockwave, Storm Bolt, Spell Reflect, Intimidating Shout, Piercing Howl, Berserker Shout, Battle Shout, Rallying Cry. Now I get that it would need for you to switch some things around to get some of these without gimping your DPS too much, but they’re still options that are there to be taken.
In regards to arms as a spec, sure, we suffer from investing all in to ST or AoE and nothing in between, so maybe pick depending on your group setup. So what if the DH in your group is doing massive damage, but if you’ve got strong priority target damage, then you’re still helping the group progress.
There’s a couple of builds you can use. If AoE is what you want, you’ve got Fervor of Battle, with slam talents and Sweeping Strikes up, it allows the slam to cleave while keeping up a decent amount of AoE damage, while using Cleave to help keep Deep Wounds applied to everything. You could try the other type of build that is more ST focused, but still have strong cleave damage with Improved Sweeping Strikes and Collateral Damage, while taking Bladestorm to use as a CD for more or less every pact or two. Collateral Damage helps save up a juiced up WW to use.
The only real thing that needs to be addressed when it comes to arms, is the fact that before 35% on a boss, we simply don’t have a way to spend rage since the nerf to Ignore Pain.
Explore the build more, there’s more options to use outside of copy/paste guides on wowhead, find what works for you, or get carpel tunnel from playing fury instead.