If a person were to do some reading, for instance on the Kumho 857 in "other" markets ( UK, Germany, pac rim countries, etc ) we would see that tire marketed for trucks and vans. Not trailer use. Only in north america does kumho usa market it for trucks, vans AND trailers. We might be able to conclude from this, that it is a commercial truck tire, first and foremost, and that the USA arm of the corporation understands that it is also appropriate for trailer use, and therefore markets it as such.
To me, all products I purchase can be looked at from the standpoint of "how can I improve my odds of success ?" Over the years, one thing I have learned is that buying products that are tested to higher standards generally improves my odds. To some extent, it often comes down also to "you get what you pay for".