The debate over the legitimacy of slavers as targets has practical considerations on both sides. While it's generally deemed bad form to assassinate writ-bearing agents of the slave trade, accurate target identification is a rare luxury on the battlefield.
It goes without saying the life of a highborn must always outweigh that of the common slaver. Certainly, when the position is reversed, the slaver does not hesitate to enchain or murder a young noble in the badlands.
At the time of publication, political pressures surrounding the protracted Neo-Carthag project, have forced slavers to significantly increase their headcounts. Therefore, it is this guide's firm recommendation that unaccompanied young lords must always shoot first and only identify their target after the smoke has cleared. One can always breed or hire more faceless brutes to wrangle maula, but our noble youth must be protected and cherished as the future of the Imperium.