Kingwouldbe uses the 2 fletch arrangement (to good effect by all accounts) I use 3" parabolics myself. I fletch in a 4-fletch, 90* arrangement. I must admit that getting my bareshafting right was a lot more critical, but the advantages I've found far outweigh the extra work involved (You only need to bareshaft once. When it's right, just note down your weights/measurements for next time.
I've found that the small fletches fly faster, flatter, quieter & don't flatten down so badly in the wet. I shoot the big Magnus 1 two-bladers, 99% of the time & have zero trouble wih stability.