I had an idea, but I think it's more in the realm of fantasy. A program that recognizes all occupied/unoccupied/duplicate NCF slots for creatures, with the ability to transfer them to another ID. Plus, with this program, you could:
UPD: OMG... Well, this is just 18+... The first matches have been found. Dark Paladins and Dark Guardians in the sequel to Hancock (those who watched might understand). Now you have to find a free slot((((
But automatic search is possible. You run it, and in the end, you get 3 files and a bunch of warnings during the process if something is wrong with the xdb, or if, for example, the file name is written in all caps somewhere (this is not a big deal). You specify the paths to the heroes, and then you look at list.txt, duplicates.txt, and errors.txt; it will be much easier than going through all of this manually.
I also added my own samples.
As for all these updates, alternative versions, and 3 upgrades, you can create them yourselves later. Personally, I don't need them at all.
UPD. I also added the Russian text.