Sorry but no thats not "totally" true, that "mostly" helps the bind at the frame, not at the axle. If you want to eliminate bind at the axle you have to build it with one upper attachment point at the axle, like a three link is, not two points like "most" Radius Arms. Yes longer arms help because longer arms twist the housing less, which is the whole idea with a long arm suspension in the first place.
A Radius Arm suspension while articulating like in rock crawling will tend to twist the axle like a torsion bar. This is not lessend by converging the links like it would be in a Triangulated 4link. To help avoid binding at the frame converging links do help but some kind of flex joint should be used at the frame while a more solid mount is used at the axle, like a bushing. Usually the larger the bushing the more deflection it will handle and allow for more twist of the axle, which would help articulation, but could hurt streetability when those bushings become worn. This design is a fine suspension for street use offering little brake-dive because of its usual high anti-squat.
