I understand the basic idea, AAT and all that. I'm just saying that if I set out to describe and rank the ways in which people express disagreement, "I agree" wouldn't be on the list.

Edit: That is, it's not that DH7 assumes the argument is wrong, just that you disagree with it. As long as you disagree, it's generally "better" - less logically rude - to use higher levels of the hierarchy than lower. If you find that you can't, then it might be time to update towards your opponent.