It wasn't an either/or decision. They are free men that are fighting for Dany of their own free will.
but you deleted a part of my post. they arent even humans anymore, they were so brainwashed. i dont even think they are capable of making such a meaningful choice. i dont want to over analyze it, it just made me wonder.
Everything about tonights episode was flawless!! It made up for some slower times, they really caught up, I'm thinking they won't split it into two books!