The rule (as I understand it) is "if there's more than one of them, give the GM the dice pools instead of skills," so that it's easier on a GM when he's trying to keep track of a half-dozen (or more!) bad guys in a swirling melee. FWIW, for most mooks we also don't bother with listing every fiddly little skill they're likely to have. I try to include a social pool (largely for defense) in almost every NPC, but other than that we heavily, heavily, focus on stuff that's likely to come up when the PCs try to kill them; perception, attacks, etc.
But "If there's just one dude, format it as a normal character sheet write-up," so that Sting or Belial or whoever has full, detailed, stats. Often those stats can have interesting plot hooks right there in 'em -- an NPCs knowledge skills can be used to flesh them out in role play, an NPCs qualities sometimes say interesting things about their background (like Rook's arm), etc, etc.
So the idea is -- and I'm not saying it's perfect, just that it's what we're shooting for -- that hordes of mooks get easy to read, to the point, "here's their die pool" stats, where full-on important, named, NPCs get the more detailed treatment. I'm sorry for any confusion or lack of fun it causes, but it's the general idea I was working towards.
