From my point of view (and I think this has been backed up by various Battle IMMs, though I couldn't point to the exact post) is that if a mage is:

1. At perfect health.
2. Not actively in combat.

It is always fair to strike them. Now, a Villager who has "claimed" them may have an issue with that, but that's not a matter of parity, and that doesn't really enter into this argument.

The result of this is that, no, I don't think attacking a healthy mage who is spelling up a slept opponent is ganging anyone.

Nor do I believe, in any way, shape, or form, that waking up someone who is slept could be considered a breach of parity by any stretch of the imagination.

Again, a given Villager may have an issue with being aided in this way, and any follower of Thror would need to heavily weigh what it means to ask for or give help in this situation, but that's a matter of religion, not of anything relating specifically to Battle.

Now, please keep in mind that I'm not a guy who is playing Battle looking to skirt the rules of the Tablet or the Plaque. In fact, I've been taken to task by other Villagers for NOT aiding when it COULD have been justified, because I felt that it was too close to the line. I've also had my position backed up during at least one of those times by a Battle IMM who watched the whole thing go down.

So, I'm not looking to game the Tablet, per se. I'm just letting you know how I see it and how I think the cabal IMMs see it as well.