I had a luck of 8 on all the encounters I got.
Pip boy - you can get the encounter with a full party, but you have to have a free slot to take him with you. So you can encounter him, go back to base drop someone off and go pick him up, then dump him in the recruit pool if you want. he's lv 8 and I'd hardly call his stats "average" since he has a 10 luck, the rest of his stats are pretty average, but he also has "bloody mess" he can wear armor you just don't see it on him..
Also had one more interesting encounter I don't see mentioned anywhere "Phil"
Phil - The Nuka Cola Guy, he was ridding a red bycycle with a cart of Nuka Cola, he has 100 nuka colas 20 molitovs and 1 fusion cola. Taking the Fusion Cola results in a temporary
ST +2
PE +3
EN +5
CH -2
IN -2
AG +3
this only lasts about a day or two game time though. It also said I was addicted when I took it but it didn't show up on my char. This is all good as current CH and IN don't seem to affect anything - only your actual...
Also trying something with four horsemen, I'll update on that later...
After getting all the other encounters I'd seen mentioned like Deathclaw liberation, B-1000. I started getting Morte, just the floating skull from Planescape:Torment, but you can't do anything with him besides kill him and you just loose faction for that. Every special since has been Morte.