OK, let me try this way.....
examples of a symetrical core is the Swamp Monster, inferno, Throttle, THING, Sonic X.
examples of an asymetrical core are Freak, Hercules Mutant, Super Freak.
Let me ask this question then, The X Factor, It has that center piece (the flat circular piece) in the core that only goes through one side....but if you turn it around, it is futher out on one side and the other side has the flat area, would this make it symetrical or asymetrical?
I hope I worded that well