Reverse Engeneering HoMM 3

The title seems to be written correctly. There are some very interesting questions regarding the "physics" of Heroes, and the answers can probably only be found by studying the executable file. I don't currently have sufficient knowledge in this area. If there is anyone who can clarify the question of how the Skilling Tree is constructed at the beginning of the game (what rules and probabilities are used), I would be grateful to that person. I think the esteemed AmberSoler would also be interested in this (perhaps with the inclusion of this information in FizMiG).