assign_appropriate_councillor_position_effect

assign_appropriate_councillor_position_effect = {
	save_scope_as = court_owner
	$NEW_COUNCILLOR$ = {
		save_scope_as = new_councillor
		switch = {
			trigger = highest_skill
			diplomacy = {
				choose_and_assign_appropriate_councillor_position_effect = {
					PREFERRED_POSITION = chancellor
					FALLBACK_1 = steward
					FALLBACK_2 = spymaster
					FALLBACK_3 = marshal
					FALLBACK_4 = court_chaplain
				}
			}
			intrigue = {
				choose_and_assign_appropriate_councillor_position_effect = {
					PREFERRED_POSITION = marshal
					FALLBACK_1 = spymaster
					FALLBACK_2 = steward
					FALLBACK_3 = chancellor
					FALLBACK_4 = court_chaplain
				}
			}
			stewardship = {
				choose_and_assign_appropriate_councillor_position_effect = {
					PREFERRED_POSITION = steward
					FALLBACK_1 = chancellor
					FALLBACK_2 = spymaster
					FALLBACK_3 = marshal
					FALLBACK_4 = court_chaplain
				}
			}
			martial = {
				choose_and_assign_appropriate_councillor_position_effect = {
					PREFERRED_POSITION = spymaster
					FALLBACK_1 = steward
					FALLBACK_2 = chancellor
					FALLBACK_3 = marshal
					FALLBACK_4 = court_chaplain
				}
			}
			learning = {
				choose_and_assign_appropriate_councillor_position_effect = {
					PREFERRED_POSITION = court_chaplain
					FALLBACK_1 = chancellor
					FALLBACK_2 = steward
					FALLBACK_3 = spymaster
					FALLBACK_4 = marshal
				}
			}
		}
	}
}

As written in game/common/scripted_effects/00_councillor_effects.txt.