Well now, it’d be remiss of me not to try and grab that Human for the Kul Tiran Marine Corps! We’re as the name suggests, part of the Alliance’s premier maritime force, and we’re open to Humans from all Alliance kingdoms (and Dwarves and Gnomes in not shieldbearing roles). Our thread can be found at Kul Tiran Marine
Expanding a little to include the Ren’dorei, there are plenty of other military style guilds out there. To name a few (apologies, I know there are a lot more of you!):
The Tideforged Corsairs are the crew of a Kul Tiran frigate under the command of Captain Jaggerhawk, who ply the waves in the name of the Alliance. All round brilliant chaps and chapesses.
The Twelfth Penal Company is, as the name suggests, comprised of criminals dragged from the Stockades and put on the front line to commute their sentences. Very good idea if you decide one of your characters has been in a bit of trouble.
The Seventh Legion, Sixth Cohort, under the commander of Theon Morningstar. Another good military guild based around the veteran organisation of the same name.
With regards to your Mag’har, the one guild I know well are the Orcs of the Red Blade. They’re a mix of the old clans, and truly take Orc lore to heart, digging down into the spiritual and shamanistic roots of the Orcs.
So, good luck finding someone, and again, welcome. 