My plan was to have had Sarah Lyons branch off with enough of her people when Maxon took control, basically leaving him with maybe a few parting shots between the two before securing the Capital Wasteland and taking the last 10 years to keep that power base better secured along with its resources. Works with the locals, protection for resources and assistance thing, maybe trained the guards at Rivet City, salvaged the Enclave stuff from Broken Steel (walker and orbital strike were blown to bits though, because that'd be too OP), probably expanded numbers because "screw Maxson and the mainstream brotherhood" and trades with or is actively studying the zetan mothership due to the Lone Wanderer's help but the ship's death ray and crap aren't functional anymore for non-OP-ness reasons. Etc. 

Idk about the Pitt though, the Pitt player and I could figure out something for if the Lone Wanderer even got involved there in the first place. If the Lone Wanderer never got involved then I feel that gives the player of the Pitt more freedom in turn to do things over there maybe? Too tired atm to think more. XD