Hello,
More history and theorizing.
I believe the B-lion by the Hubard Bros. folded in the middle and may have had aluminum beams. The hulls were canted too. Also the Shark is not a B class cat- too much sail area.
About the beam widths...the wider boats need to be built heavier, but can handle more sail area to windward. If you just put narrow beams on a wide boat it would be over built for the forces that would develope, and thus not be as fast as a boat designed specificly for a narrower width.
For example A cats are light, narrow, and fast.
For overall sailing in the long run, if you built a special tornado lighter, maybe a shorter mast, with 8.5' beams i wonder if there would really be that much different than a stocker? prolly depends on how light, and how often you sailed in really strong breezes.
happy holidays