all 3 of those guys got hurt. As was said, Curtis and Dillon did well in 04, Priest has still been predictably injured and predictably excellent when healthy. Supposing they all return in good health, it'll be very interesting next summer.
Personally, I'd trade Priest if I were a Chiefs exec. At a minimum, there's 31 teams that would use him as their goalline back without blinking an eye. All 3 if healthy and "sharp" will be hard to bench. Martin's a HOFer, Priest has had "best of" seasons, Dillons consecutive 1000 yard string is quite impresive too.
I've never cared for RBBC. I wouldn't be surprised if these 3, or 2 of 3, are annoying next year for FF. Coach thinks "How do I sit a guy THAT good?" and also "How can I ignore his age and not work the younger back, no RB=no job for me"....eventually it's a RBBC that just stinks.