When Orcus isn't enough, add friends?

This post over on Old School FRP Tumblr caught my eye:

The Four Horsemen of the Apocalypse

They're actually the four horsemen of Orcus.

Just eyeballing them vs. AD&D 1st edition's Orcus . . . I'm pretty sure they're a very serious threat to him. He's got 85% magic resistance and excellent combat abilities . . . but a 23rd level magic-user and everyone with weapons that can hurt him, even the summoned minotaurs . . .

Good thing they're Chaotic Evil, like him, so cooperation isn't likely to go very far.

It's interesting when you beef up a powerful unique monster with a coterie of allies who are also seriously powerful. I think in a way it diminishes the main monster, though. Instead of Orcus being a boss fight you can just have, there is this other layer of guys you have to get through first. So now it's a bit of an extended encounter. It can be another excuse to push off a fight like that later and later in a campaign. Put it off long enough, and you won't ever get to the big demon. And if it goes from "very tough encounter" to "campaign culimation" than they can't have 85 HP and go down in a 10 round melee. You need them to have hundreds of HP, piles of allies, more powers than can be handled . . . and the PCs need to escalate to match.

I've been trying to front load the scary stuff and even then it's tough to get people to engage. So while I like the idea here, I worry that it's just another way for the PCs and the GM to back off from using the cool unique monster that is Orcus.