What do you consider the original? Can you share a screenshot if you have one?
Well, there's the skill file that comes with the official version of the game in the fandom documents folder. I don't know who put it there or when, but let's assume that this is the original skill file, since it's in the root folder with the definitely original official version of the game. And whether there was a skill file for version 1.6, I don't know, included in the package? And in version 3.1, there's a skill file 3.0, and is there a skill file version 3.1 from the same people who made version 3.0? I've been hearing these stories about skill file version 3.1 for about 10 years now, that 3.0 is incorrect, and 3.1 is needed. But I've never personally seen this original skill file 3.1. Where did these rumors about version 3.1 come from?
UPD: Hatabych asked a good question, and I became curious, so I decided to find out where all this originated. In general, there's a Heroes fan from France with the nickname Aurelain, who made these skill files. These skill files were later recognized by the developers and added as a kind of official one to the root folder of their game in the "Tribes of the East" add-on. In the original Heroes and Lords of the North, there was no skill file in the root folders, BUT Aurelain also made them for them, and I even managed to find information about the existence of a skill file for the "Heroes 5 1.0" version
and since there was one for 1.0, I think (well, I hope) he made one for 1.6 and for 3.1 as well. Apparently... this should be considered the "original" skill files... I have no other ideas.)