In those multiway pots, the small PP's were actually the favorite. AK loses most of its value when it gets called by 2 hands. S&M, in their books, claim this is so but they don't tell you the specific reason why. The answer is quite simple. In a multiway pot, AK is only good if there are no pp's in play. If you're in a pot with AK v. KJ v. 55, it comes out 3:2:4 as the rough equities. (Having AK suited adds 5%, almost making it a cointoss between 55 and AKs). In layman's terms, going all-in with AK in this spot is like calling a preflop all-in with 9 10 suited against AK. It's better to play two high cards from late position because it will allow you to better gauge the number of people who will call. Today, I would probably limp with AK from early position.

I'm pretty sure this is why Fnord stressed pocket pairs like TT and JJ; they're a MONSTER favorite in a hand like JJ v. KJ v. 55.