I mean there's a bunch of solo players who have been grinding outside too. There's that 55mage that's been grinding murlocs in... the swamp area(forgot the name been so long) and since 50ish has been grinding undead in plaguelands like virtually everyone had to do at one point when solo questing cause you run dry in the last 5 levels anyway. That shit's great for mage solo aoe, paladin prot(not sure if it was vanilla, but I want to say yes? just the spec is suck at everything else) and hunters might be grinding somewhere else cause they don't really aoe so they don't care as much about density as long as they're alone in the spot.
And I thought you needed ony cloaks on tanks for something in MC but thinking about it I'm not too sure anymore, I guess it was just for BWL?
Anyway not sure there will be a method kill this weekend, them fucks look pretty far behind on leveling, a few groups are higher but some are still lower 40s, and 1-40 is like as long as 40-60(shorter even iirc, breakpoint was around 45). I think the keying process in original vanilla was still fast cause you could enter BRD/UBRS with a raid so you could key everyone fairly quickly but still that's gonna be a bit of time. On the plus side MC itself is such a fucking joke of a raid compared to shit they made later on(even during vanilla) that I doubt it'll take very long to clear once they can get started, probably a couple of hours.