...your sole purpose there is to carry the other two?
I like dpsing scenarios, and this isn't about whether or not scenarios suck. I play a plate character, and every time I get grouped with non-plates (even with one other plate), I become the de facto 'tank'. They follow me everywhere, wait for my pull, etc. Very rarely do I get queued with someone who heals, so most of the time I am trying to keep myself up (because aggro never leaves me) and do tank stuff. And still end up doing most of the work in clearing the scenario.
I tank 5-mans. When I queue for scenarios, I want a 'role-less' group, dammit. I got queued into a group once with two other plate wearers, and that was a joy. Aggro was shared, and sometimes we'd split up and take care of our own different groups. It was so quick and pleasant.
My guildmate isn't 90 yet, so we can't queue with her yet.