Ok I am trying to decide between the tanks to play. So lets say you had a guy that had all 3 of them leveled up and geared. He was good at all three. Which would you tell him to bring along for your group?
Hot take: he's not good at all three. He should be a paladin because there are no paladins so people can't contrast him with legit good ones.
If you have a spare heroic you could try each one and see if you have a preference. I started a SK and a couple of years ago I tried a Warrior & Paladin but I preferred playing on my SK. My Paladin got to 97 and my warrior to 88 and this was when TBM was latest expansion.
SK is the best choice, in all situations, including boxed group. The SK have a plethora of AE aggro abilities that allow you to not have to wait for the only good warrior's AE aggro ability to refresh before pulling a new wave.