slim mason
I believe this is only possible without quick-start, because you get a additional follower during the tutorial segments, thus allowing you to have 7 - enough for anura, and thus proceed to every other area without killing a bishop, including plimbo, where they talk about the lamb killing bishops and it messing up their trades etc.
My first thought is to give plimbo different dialogue that doesn't lead to anything else directly if no bishops are killed. (please don't make the entry for anura require 8 followers)