To the original question - I've tried both, and so far I much prefer the chief. He can land in smaller spaces, can have magic items, has better leadership, and won't take a panic test from a single wound at range. Also he could help reign in Predatory Fighters. As to what role the chief serves, my local meta (just me and my brother so far!) is very cannon-heavy (he plays Empire w/ two Great Cannons and a Steam Tank...). I use the Chief to "hunt" the cannons (in practice he distracts one or two of them until they inevitably kill him... Hopefully not before he moves on turn 1). I kinda want to bring 2x of them, to be honest, but I don't want to over specialize.