let us clear up this datnoid fiasco. The chart tell us the general look of a perfect datnoid. Either it is an indo, pulcher, microlepis, thin bar, new guinea, silver and the rest. The tail is based on personal judgment.
The bar which is more important than the tail, is what we should be looking at.
This is the most major mistake everyone makes. DO NOT COUNT BARS, and DO NOT LOOK at the Body bars.
First off, if you are really good, you can tell by just looking at a body shape, but this is not prominent on very small dats. On smaller dats, you can look at the very last stripe, and if it bleeds into the tail, it is a Datnoides Pulcher. 100 % positive identification.
QUESTION #1: For example: If a thin bar has a tail like pulchers, will you consider this widebar?
Uh..it's a thinbar
Next, if a widebar has a tail of a silver datnoid will you consider it widebar?

No, it would be a mutant, a hybrid, a nuclear accident.
Again, you cannot expect a perfect tail in the end. Some will have perfect tail markings and some don't. The majority of your decision should be based on the wideness of the bar and not the marking on the tail. But, this is my opinion. Those charts were also based on people's judgment.