07 E450 Class C rear air bags better handling while towing

Although, for some reason it seems like cutaway chassis seem to have finicky front ends and steering.
See alot of cutaways with bad tire wear. Including a relatively new E350 box van my buddy has. Front wheels are massively positive cambered. Like the front end is going to lift off.
Rear springs look like a frown. And he don't have all that much weight in it. Maybe 4000lbs (unless he loads up on parts for a job) and the heavy stuff is in front of the rear axle.