When we try to use powder in many different cartridges and with a range of different bullet weights, we call that type of work a "parametric study", which means we try to use parameters to model the internal ballistics. You can't use just one parameter to describe the powder and that creates this problem. Even the different "burn rate" tests cause a difference when the context jumps between cartridges or even different test facilities. But don't let it bother you.
It isn't really possible to give an exact rank order or "burn rate" chart for smokeless powder. The ones they do publish are not bad or wrong, they are just interesting. They are not a bad way to simplify the discussion, but they are not meant to serve as loading data or powder substitution.
To be useful without regard to what cartridge, bullet, seating depth, primer, jump, etc., is not possible, but it is close enough for marketing purposes. For example, there is no clue in the burn rate charts with regard to powder packing factors or density. Two powders might be next to each other, but without the packing factor or density, what do we really know?
If you have an interest in understanding what the burn rate charts are and more importantly what they are not, you can get a pretty fair understanding without getting a PhD by playing with Quickload and or Gordon's Reloading Tool, or a text book on internal ballistics. YMMV
