>>543694124
The most famous and powerful Primarch in the setting is an Iconoclast character,Guilliman makes frequent political choices that would've him killed if he wasn't the literal son of Empy and would be viewed as Heretical.
The invasion of Nurgle into Ultramar is basically gorilla making the same choice that we can make on the lower decks to fight off the growing Nurgle corruption with things like medicine,rations and keeping the whole place less shitty. Radical choice is just ignoring the whole problem