Changing a skill in a campaign.

Regarding unlearning a skill, I tried entering it in different ways (with spaces, without spaces, etc.), but it gives an error and nothing happens. I tried changing the tactics to frenzy in the datapack (found mission 1 of campaign 5), but when I launched it, Fidaen had both tactics and frenzy. I tried to find a mod, but I couldn't. If it's not too much trouble, please provide a link. Thank you in advance.