Dogenator, try experimenting with Dugalu, using Haggesh as a template (<CentaurMistress_StartATBBonusPerHeroLevel>0.01), and insert <Archers_StartATBBonusPerHeroLevel>0.01 into DefaultStats. Put the special ability name at the beginning, and take the rest from the others, as needed. It's nonsense, of course, but who knows.
In theory, it shouldn't work like that. If the function isn't created in that format, then using an empty value won't work either.
It will be funny if it works 😂