Ok? The motorcycle endorsement is already a separate tier. I don't think there's anything wrong with operating a box truck on a regular license. There's not that much difference in vehicle operation (still hydraulic brakes, etc), just some additional emphasis on load distribution, engine braking, and speed/braking distance - which is still important in many smaller vehicles. I do think the regular license test should be more rigorous, since it doesn't even cover these topics sufficiently for the smaller vehicles.