Opinion on weights for TV/5th wheel combo

So you can drive a 30k class A with a V10 but not a truck and trailer??? If a loaded pickup sinks below level on the springs you are way overloaded??? Based on these theories all single wheel trucks with truck campers are overloaded. Tri-axle trailers transfer weight different than tandems and toy haulers load cargo weight different than regular 5th wheels. I see a lot of talk about pin weight but never see anything on here about hitch position in the truck for weight transfer to the front axle for control. All them 3/4 ton trucks with tools and equipment for work always are checked before use on a scale before use and adjusted to the manufacturers tag on the cab correct. Too much talk on here about auto self destruct for a few pounds over without looking at weight movement on the combined unit 1st. We traveled well over 100k miles with rv's, campers, flatdeck and horse trailers with 2500 diesel trucks equipped with airbags and none of the issues claimed here. A 1 ton dually will handle the weights with more stability but not everybody can have one and not everybody needs a huge rv to live in but that should be blamed on a salesman.