The Brabazon DIDN'T needed the counterweights, but the burocrats feared a plane working the control surfaces with only hidraulic power, that's why the control surface horns varied in each picture, because they where a real dead weight that degraded the working of the plane but were imposed over the Bristol company.
The plane was ordered by the goverment. The Bristol company didn't want to build it, and the british companies didn't wan't to use it. That's why, being so good tecnologically, it never went into production.
https://www.airspacemag.com/history-...tee-118026858/