For me, therapy is collaborative, as Lolagrace said. It would certainly be very uncomfortable to see my T as "opposed" to me rather than working on my team.
In schema therapy the concept of lifetraps means that the client can distance themselves from unhelpful thoughts and behaviours by labelling them as lifetraps. Then the T joins WITH the client to attack the lifetrap. It's important because it means the T and the client are on the same team, and it clarifies that fighting against a particular thought or behaviour does NOT mean opposing the client. I think that distinction is very important.