Hop on any Sims forum like Mod the Sims or The Sims Catalog and you'll find all sorts of Sims 4 mods for decor, careers, houses—anything that isn't limited by the imagination. There's Fallout-inspired furniture, Game of Thrones clothing, even mods designed to making WooHooing riskier or let your sim to go on a murderous rampage without consequences. And now, thanks to modder N.Blightcaller, you can join the Horde army from World of Warcraft. (Move over, Sylvanas. There's a new warchief in town.)
N.Blightcaller has two different versions of this career mod, but the main one is heavier on the roleplaying and requires the Get To Work, Get Together, Outdoor Retreat, and Spa Day expansions for Baking, Dancing, Herbalism and Wellness skills. You won't need these skills when you first start off, but you will need them as you advance in your career.
As N.Blightcaller describes, For the Horde career progress works like this: you start off as a scout. To get promoted to a grunt, you must level up "Fitness to 1 (to stay on the move), Painting 1 (to map out camps), Cooking 3 (to stay healthy on the mission), Logic 2 (to decide the safest path), Charisma 1 (to charm locals)." The further you get promoted up the ranks, you'll need to level up additional skills.
One thing that makes this 'For the Horde' career path different from others in the Sims 4 is that it doesn't stop at the tenth promotion. Once you reach the rank of champion (the ninth promotion), you're given two career branches to choose from: you can become Warchief of the Horde, or the Champion of Azeroth. Their career progressions look like this, with Champion of Azeroth having more steps:
Warchief: Lieutenant General -> General -> Warlord -> High Warlord -> Warchief Champion of Azeroth: Champion of the Eastern Kingdoms -> Kalimdor -> Outland -> Northrend -> Pandaria -> Draenor -> the Broken Shore -> Zandalar -> Champion of Azeroth
If you can't imagine yourself pledging loyalty to the Horde, even outside of World of Warcraft, N.Blightcaller also has a career mod for the Alliance that only requires the base game. You can become either Champion of Azeroth or the High King/Queen of the Alliance, depending on the career path you choose.
Also, The Sims 4 is currently free on Origin, so now is a good time to fight for the Horde or the Alliance, Sims-style.