A 6 wheel chassis?

I think at slow speeds a cutting brake type system would work fine on tracks...........In the Holbrook 6 wheel drive Jeep it had an auto Trans. with Powr-lock limited slip diffs in all three axles and had a brake pedal on the right in its normal position and on the left where the clutch was another brake system was installed.......push left pedal and it steers left and push right and go right.......he also had valves under the hood to shut off the steer axle brakes.
Years back in Baja I was pre-running part of the course for a friends race team......basically playing as I was going to drive one of the chase / support vehicles ! I was in a live axle 2-seat buggy powered by an air cooled Porsche motor. 125-140 mph out on the flats.......... the front end was so light at speed the front tires were of little use........steered via a single stick cutting brake between the seat ..........push forward turns right and pull back and go left......very effective!

 

I am A Military Vehicle Preservation Association guy too. Last year there was a cover photo on the MVPA magazine of a M38A1 front end with a long frame and a dual axle rear with a cargo bed like on a wc52. The photo was of a Viet-Nam era Air Force base. It was used for moving supplies under the planes. I hope that helps.