hong said:There are three kinds of people in the world: those with red, blue and green circles around their feet.
There are two kinds of things in the world: those with circles around their feet, and those without.
Rats in bags do not have circles around their feet.
But no one ever suggested that you attack a rat in a bag. You need to take the rat *out* of the bag. We have examples of rats-out-of-bags as having circles in WotC modules, and 4e will be full of small sized minions who most certainly have circles.
BoR is merely shorthand for situations where it is to your advantage to be surrounding by allies/enemies who are too weak to, by their own actions, affect the tactical situation. Once those situations exist, it is to your advantage to import such creatures. Rats are merely an evocative and compact means of doing so.