Spells that try to correct the HUGE problem of pet survivability should be given to all pet classes. This includes Mammoth Guard and it includes Spellbreaker's Guard.
There is absolutely no reason that i can see to give any other pet class a form of Promised Mending. Beastlords are a wisdom based class, the same as all the healers. Int casters are primarily damage based. There is no reasoning behind allowing an int caster to heal even CLOSE to the ability of a wisdom caster. Promised Mending type spells are currently unique to wisdom casters and should stay that way, at least for now.
You guys are also crazy to think that beastlord pets pose some sort of "threat" to your pets. A magician pet will hands down out tank, out dps a beastlord pet, no doubt in my mind. Sure, your pets are no longer twice as good as ours as they once were .... but they never should have been twice as good to begin with.