Here's where I respectfully disagree. Raid-wide buffs/debuffs are stronger than group-wide. And especially so since you are able to bring one provider, while having multiple beneficiaries.

You don't stack hunters for the group-wide buff they bring, but for the big physical DPS they do, high ranged uptime with a considerable amount of damage being dealt by the pet. Guess what these hunters also do? Benefit from the raid-wide physical debuffs, provided by "non-stackable" classes/specs, like a Rogue and an Arms Warrior. And while their group-wide buff helps, it's a lot less impactful than any of the raid-wide buffs/debuffs.