There are some things that you have said that are correct and others that are not.
Kato, Atlas, P2K, and all the other plastic loco makers will produce a loco that will be close to or maybe even match a certain RR prototype. Then they will offer this loco in several other RR's livery to help offset the cost of the tooling. That explains the detail in the wrong location on your Atlas. They may even go as far as to include the detail that would make the loco correct for another road. Some research and some work with a knife, files, and pin vise would easily correct any discrepancies.
To try and produce a loco that was completely correct for every single RR that had one is too expensive. To do so would then drive the price of individual models way up due to having to "pay off" that tooling cost with fewer models per mold used to make the model.
Detail comparison on a model from one maker to a model from another maker is a
very subjective matter. I've seen (and sold) many, many Katos with almost no detail except what was cast on, to engines with many add on details. Plus if you don't like the material that a detail is made of, ie the plastic grabs on the P2Ks, there are several detail manufacturers that can probably solve that problem for you very easily.
Overall my point is, that determining who's the best, is totally subjective and no matter how many responses a thread like this gets, you won't get anyone to change their minds.
BTW, what do I think is the "best" diesel?
Every one I own!