Obviously need a tank spec.
Then we need a melee DPS spec. Should have 2h and dual wield options
3rd spec should be support with banners, rallying shouts and some ranged dps options. Shouldn't compare to a Ranger but can do ok damage while giving buffs to party members and being ranged. A battle rez would be a cool option for this spec to make them viable without overpowering them. (long cooldown)