At the moment it’s “The Artful Dodgers” for me, made up of one captain and 11 Dodge and Nimble melee guys.
My other favourites were: “Hugo’s Headhunters”, using Head Hunter and Push the Advantage perks (and named after the ancient Battle Brothers hero Hugo from back where half the roster seemed to be made up of Hugos ;-), and “The Reaper’s Legion”, with the scythe banner.
So little time, so many perk combos to play with.