Your chest piece has a randomly generated boost type (something like _boost_scoundrel_large). You could mod it so that boost gives warfare instead. But then this applies to every gear and essentially removes scoundrel +2.

What you need is savegame editing. I have done it a few times. A bit tedious to find a specific item in wall of text. Look here for how to extract your save file: https://docs.larian.game/Pak_Extractor_Guide
Though it isn't easy.