i think i know the answer but want to be sure for my next game: Does a Skink chief on Stegadon get look out sir in a thunderlizard list when a stegadon battleline is near by?
Yes. If a hero, that is not a behemoth, is within 3” of a friendly unit that contains 3 or more models (so a unit of only 2 guards will not give look out sir)
It wouldn't work with stegadon regardless as they're 1 model units so they can't give look-out sir to anything.