I'm touching on the Garithos topic once more and then never again, because at this point it's getting ridiculous.
Garithos was a thug on a horse who got by thanks to the support of the political connections humans as a race had inside the Alliance of Lordaeron. That's why he got people from Khaz'modan and Silvermoon, no matter if he saw them all as expendables to ensure his band's survival, or his own.
By the time Sylvanas gets in touch with Garithos, Garithos is mind controlled. This means that the man is done for and his followers as well. Garithos being freed by Sylvanas is a fortunate circumstance turned tragedy, because not knowing when to back off and count his luck, the guy decides to aid Sylvanas and lay claim to Lordaeron.
And here's the cherry on top: Garithos got mind controlled because he overextended where nobody could cover for his blunders. Had he succeeded in whatever he was trying to do, he would have become Nameless Ghoul #7, only useful to complete whatever quest there is to do around Caer Darrow.
And on topic, this whole discussion is one of the most disheartening things about Forsaken lore: Calia is seen as fine because the Forsaken are perceived as expendable in the overarching plot: past villains who need no development because "lol the Plague Sylvanas fanboy tits and ass amirite".
Years of nuances thrown under a bus.