[HoMM V]9 Race - Swamp! Is it needed?

To make a mod with a new race, I need the game source codes from Nival! That is, I need to see how Heroes 5 was written! And that's already a problem! For starters, I at least need to see what is inside the file with the "data.pac" extension! These files are located in one of the game folders!
And now about the Swamp! I'm thinking of giving it a building that will destroy artifacts for any resource! You could also add a building that turns any creature (except Necromancer and mechanical creatures) into a troglodyte! And one of the swamp heroes' skills would make it so that creatures turn into upgraded troglodytes! I haven't come up with the main skill for the Swamp heroes yet! But I have some thoughts about reducing the initiative and speed of hostile creatures due to swamp slowing! If anyone has other suggestions, write them!:)