On my current playthrough I went straight to Diamond City, bypassing Concord and the start of the Minuteman quests. By the time I got around to starting Concord the Prydwen had already showed up and Brotherhood patrols where out and about. So I go into the building in full BoS power armor with minigun - Sturges is a little miffed at that and the dialog changes, but when I exited to the roof of the Museum by chance the random encounter where BoS troops drop down at the Concord church from a BoS Vertbird had started. Between me and two other BoS knights the raiders didn't stand a chance and Neither did the poor deathclaw what with one of the BoS boys packing a gatling laser.
It was glorious, and hilarious.