To some extent I agree with you, but I do disagree on some aspects.
The different bodies provide a sense of individuality to that driver. At the world finals, the different bodies helped with driver identification (But I still think the flags did a good job of that). The different colored El Toro Loco and the Max-D bodies set those drivers apart from one another, and gave them kinda their own identity. This holds true with Dennis' chrome body compared to the rest of the Digger fleet. IMO, I kinda think if they're doing away with the secondary colored bodies, then there shouldn't be a MM Dalmatian or Rottweiler as even tho they're separate trucks, they still kinda in a way are a different paint job from the original Mutt. If a driver from a multi truck team qualifies for Vegas, slap a different body on their chassis, and let them run on their own.