Tips -real- hat Why hello there!
I’d love to recommend the guild Sisterhood of the Serpent (or Serpent Sisterhood in-game) as a group of Mercenary-Assassins for your perusal!
A shadowy organization of killers and brigands, the Sisterhood is nearly cult-like in its workings, but are as-tough or tougher than any other mercenary band. Comprised entirely of women, the Sisterhood are willing to take on any contract provided the price is right. Loyalty is their creed until the job is fulfilled, and the group does not discriminate from sister to buyer. They are masters in their field, and unconventional in their methods, but the job is always fulfilled when it comes to the work of the Serpent.
Being made up of all races within the Horde, the Sisterhood is a mercenary organization that pride excellence and liberty in their work. While on the surface they may appear as a group of contracted killers, their organization and themes go MUCH deeper, and their bond is just as tight as the namesake. More can be read about them here.