Raybane Spellblades are no longer considered able to off-tank after their rework. They replaced their Taunt with an aggro reduction ability, severely nerfed the mana shield thing, and still left them in only Leather. Once upon a time they were lumped in with Rangers and Monks as off-tanks, but they shifted them into the pure DPS classes like Rogue, Archer, and Wizard instead.
In fact, Wizards get a mana shield as well that has the exact same stats as the Spellblade version, one level earlier! Not that I suspect many Wizards bother with it.
Sure they can take more hits than a Wizard as a Leather class but, like, a Shaman has Chain and a Druid Leather and no one really brings that up as a big bonus for Shaman or anything, because neither class really wants to be getting hit in their group role. Likewise, neither Wizard nor Spellblades want to be taking hits in a group, ever.
Either way it's a hypothetical, I'm not the one that needs to make the judgment call on if, outside of damage, Wizards or Spellblades or other DPS classes offer more to a group. My only point is, IF there is another class that has less to offer the group in all other ways than damage output, doesn't it make sense that class should have better damage output, regardless of the original design from years ago? If that ends up being Wizard, great. If Wizards get a lot to offer a group and another class doesn't once all the reworks are done, I don't think it makes sense to still have the Wizard also do more damage on top of that, do you? That would just be plain old class favoritism.
In any case, we should drop this and move on because we're really on the same side here of thinking Wizards are pretty bad off and need major improvement. Our only disagreement is personal taste - I don't care as much about being the best at damage as long as it's enough damage to be valued by groups, and would rather have more utility (and have it earlier), and you don't really care about the utility all that much and want Wizards to be top-tier DPS. Neither of us has what we want from the class right now though, so we probably shouldn't be wasting our energy arguing about this minor difference in personal taste when there's bigger issues with the class.