I Was Dismissed from the Hero’s Party Because They Don’t Need My Training Skills, so I Strengthened My [Fief] Which I Got as a Replacement for My Retirement Money. - Chapter 24

no they are just stupid, they been training for along long time by now they should be able to fight on their own its not that hard to use your skills and some common sense, if they fail its either they too stupid or you didnt teach them anything just threw them out there to attack and kill or both