Heroes of Battle commander auras

Heroes of Battle provides an extra game mechanic called commander auras, which grants bonuses to allies within 30ft of a powerful commander. So that we can decide as a group whether to use this rule or not, I have summarized the possibilities below.

Characters have commander ratings based on how many troops they command. Because the PCs are jointly in charge of Castle Granis, I will give them each a commander rating of 4; Valdash has the same rating, even though any of the PCs is considered to out-rank him for the purposes of giving orders. Any NPC you put in charge of a squad will also acquire a commander rating (a rating of 2 for a squad of 10, for example).

You can pick a commander aura from those for which you qualify (they mostly have alignment and commander rating restrictions, and some have additional restrictions). You can't change it unless your commander rating increases (which it probably won't in the near future of the campaign).

Allies within 30ft who are of a lower commander rating than you gain benefits from your commander aura. Allies of the same commander rating don't benefit, and you don't benefit from your own aura.

The auras for which each character qualifies, and their benefits, are:

Grim
Mobile commander (allies get +5ft speed)
Opportunistic commander (allies deal +1d6 damage on attacks of opportunity)

Ug
Animal commaner (animals and magical beasts get +2 on saving throws)
Feral commander (animals and magical beasts get +2 on attack rolls)
Healing commander (when you heal, you can also rally as a free action)
Spellslinging commander (spells cast by allies deal +1d6 damage)

Verschoyle
Spellslinging commander (as above)
Healing commander (as above)

Zumm
Bloodthirsty commander (allies get +1 on attacks against wounded foes)
Goblinoid commander (goblinoid allies get +2 on attack rolls)
Melee commander (allies get +1 on melee attack rolls)
Orderly commander (allies you rally get +10ft speed for 1 round)
Protective commander (allies get +1 on saving throws)
Pursuing commander (allies deal +1d6 damage against frightened or panicked foes)

Zumm has rather more options than the others because the alignment restrictions to auras seem to favour characters who have an extreme alignment rather than one with a neutral part. If the rest of the group thinks this is unfair I could house-rule a relaxation to the restrictions, e.g. you've got to be within one step of the listed alignment rather than match it.

Valdash would have the bloodthirsty commander aura, because it's the only one for which he qualifies.

Naturally, if we start to use this rule, villains will start to have commander auras as well. Those ogres in your prison cell are starting to look a bit more confident for being in the presence of one of Jalahand's elite ogres...