>>10767769There are some unmentioned rules to consider.
The axles can't be facing eachother if they are moving, to my knowledge no set has never done this. Secondly, if the axles were only connected by half they would risk falling off too easily. Those gears already have pretty poor friction to begin with. There's an option to consider with this single towball idea to lock the axle with a bushing or extending it to where the other gear would be but it would mean gear movement like Gali's and Onua's couldn't happen, both arms would move in the same direction instead.
This would still all require a longer towball axle, preferably the length of 2 and half with the ball. Is that out of the question? Not really given some of the recent molds (picture), but I wouldn't count on it.