When two or three walkers are coming towards me in my lane, and they're walking by a group on their right where they're supposed to be, what then? You've got to stop and wait for them to sort themselves out. Walk facing motor traffic, but with bike traffic it works best when everyone is going the same direction.
People don't follow MUP rules enough to be worth the aggravation of worrying about them. When it's busy and crowded like that, the only thing I'm thinking about is my plan for getting off of it.