Why do you group two points into (c)? The difference between (b) and the second half of (c) seems unclear: what's the difference between (b) (the decider) dec

Why do you group two points into (c)? The difference between (b) and the second half of (c) seems unclear: what's the difference between (b) (the decider) declining to invest marginal resources and (c.ii) deciding that the sides-in-question are not importantly different (presumably "not importantly different to the decider"; if not, please clarify) and not worth judging between (again, presumably, "not worth judging between to the decider"; if not, please clarify) ? What's a scenario which is (b) but not (c.ii) and vice-versa?