I disagree that gladiator is better for new tanks than marauder. Paladin may be easier than warrior, but at low levels I think marauder is the way to go. Gladiator at low levels has a harder time keeping aggro even if you're doing everything you're supposed to, so if you start with gld it can be discouraging. I think if you start out as marauder and learn the dungeons and pulls, it will make it easier to do on gladiator.