Alternatively, if you set the "Game Data Set" to the Custom data, that would be the data where the Spirit Lodge trains the Spirit Walker. On that version of the data, the original 2003 game design intention was that even after a new patch comes out, the custom map would still use the old balance data, so the custom map would never change and never break.
When the Reforged guys were making 1.30 and 1.31 they didn't totally understand that system, so they probably sometimes added new abilities or things to the Melee data without adding those things in parallel to the Custom data in an available-but-not-used way. The Firelord is an example of how to do it rightly, where we can see that the Firelord exists in the Custom data, but he is not available at the tavern. That way:
- an old map from before the Firelord existed that customized the 5 original tavern heroes to be 5 custom heroes does not change in the patch
- a new map made after the Firelord was added still has the Firelord available for use in the custom map, and you can manually add him to the tavern if you want to match the Melee gameplay in that way
If you use a version of the game made by Blizzard instead of Activision, then the advice to use "Melee - Latest Patch" for your custom campaign would probably be incorrect as it violates this original design intention. For example, playing your custom campaign on 1.36 after developing it on 1.30 -- if these patches were made by the old original Blizzard devs -- would seamlessly "just work" and be backwards compatible. But because the people making Reforged were in many cases ignorant and under-funded, in reality we live in a world where it probably does not "just work." Nevertheless, by designing your custom campaign to use the exact 1.30 or the exact 1.31 melee balance stats for the units, you will be making it "just work even less" on future game versions.
In my opinion, it is worth remembering that 1.30 and 1.31 store all game art files in a new kind of storage container added to Warcraft III in preparation for the Reforged, since those are Reforged prepatches. The campaign editor was probably not a focus at that time, so it is more likely to be bugged on the Reforged prepatches like that. I wouldn't be surprised if this is the problem you're facing with "Unknown (R000)" stuff. I'm guessing if you develop your campaign on Blizzard's Frozen Throne, instead of on Activision's Reforged Prepatch, you're not going to have some weird problem like that in your data. I could be wrong; it's just a hunch.
The last patches of Warcraft III: Frozen Throne released before or at the time of the Activision merger were 1.22-1.26. I believe 1.24-1.26 were probably after the Activision merger, but possibly before Activision hollowed out the Blizzard human beings as much. I have enjoyed mucking about with an old backup of 1.22 that I found on my computer from back then, personally. The 1.23-1.26 era were added as a computer security fix to avoid getting a virus when playing the game with other people, and the Battle.net servers are gone now anyway for Frozen Throne, so given that you're probably not going to play these old versions with other people I don't see any reason not to use 1.22.
