There is many things in games, books, or movies that dont make much sence, but its esential for story. :-/
I would say Tav's leadership is certainly one of them.
But i would honestly love if our companions were more autonomic ...
And i would see no problem if Lae'zel would sudently appear in conversation with Giths saying something like "I tracked you ... you have found my kin!" and runs towards them, maybe even join them against us, if we will be especialy rude ...
Same as Wyll and Spike ... there is even excuse offering from the story, since Mizora could told him that she was draged in goblin camp ... and it kinda makes sence that he would not stay in our camp, poking fire with a stick. :-/
I still dont understand why cant we change Race for our hirelings.

Lets us play Githyanki as racist as they trully are!