No clue, but I'm going to go out on a limb and say that part of the reason for the really long rod is on how the action of the rod helps with the cast. Those centerpinners use a really funky cast that seems to me is more rod-oriented-assited then anything else.

That's my guess today, and I'm sticking too it!

Ok, I'm sure one of the real experts will chime in on how stupid of a guess that is and tell you why a shorter fly rod will or won't work.