sometime your fan N1 shaft turns one way and the N2 turns the other way to cancel out the centrifugal force. if not you will be internally pushing those rudders beyond the limit
Just had a re-read. Can you run the background to this statement past us once again ?
The Pegasus in the Harrier has LP and HP spools rotating in the opposite direction (to minimise gyroscopic precession in the hover, nothing to do with centrifugal force), but off the top of my head I can't think of any other examples.