got myself Piper after sprinting to Diamond City. What a journey that was, I passed over the bridge by the USS whatever and thought "ah cool some raider PA". Initiated with a sniper shot and when I was reloading fell off the bridge (eek). Never been so panicked in this game before. I had 5 raiders shooting down at me and the +10 rads ticking my health down. I was [censored]. I swam and got onto the ship, I thought the rads were more deadly than their pipe weapons. I lucked out big time. Where I got on board provided me cover behind some cargo containers, I popped 2 stimpacks and my "Lucky" shotgun gave me the edge when they swung around the corners. If it wasn't for the shotgun I'm sure I'd be sleeping with the fishes now.
But anyway, got Piper, thought to myself it would be a good idea to get Nick also, then I have a companion in reserve. Went to the vault and the Triggermen are pretty strong! Anyway in the lower section of the subway Piper lost all menmtal faculties and ran down to take on 3 of them and 1 legendary. Needless to say she lasted about 5 seconds, but gave me the time to wipe them out. Getting Nick out was extremely easy. Even at the end when the 4 guys show up I just ran point blank at them while they were having a little conversation with Nick and whipped out my shotgun. 4 well placed VATS shots later they were headless corpses on the ground.
I don't have a reserve now but I will probably head to the combat zone next to continue in my quest for a back-up.