A turn 5 question!

[Calib0s]

You have to swap tank death sentence and a war can't survive a hit from death sentence.

You don't have to tank swap at all (though it can make the fight easier, assuming double Paladins).

A Warrior can most certainly OT this fight, as they can everything in Coil, and honestly can probably MT it as well.

As with everything in Coil though, it is going to require much tighter execution from your healers and likely better gear than a Paladin would need to do the same thing.

[Hachiko]

There is pretty much no way a WAR could MT Twintania. Even with the best gear they wouldn't have the EHP to deal with death sentence in a reliable way.

As for OT, it might be theoretically possible, but the add phases would probably stress the healers too much, and I don't know if phase 1 would really be that efficient / effective with a WAR when they have to tank the 3 adds.