Maybe there could be new encounter called "Brahmin caravan" that got 1-2 average merchants and 3-5 scarred guards (Depends you location what guards they got)
Locations and weapons for guardsKlamath = Spear guys, 10mm pistols
Den = Sawed-off shotguns, .44 revolvers
Modoc = Shotguns, 9mm mauser
Gecko = Crazies, Hunting rifles, Shotguns
VC = Assault rifles, Hunting rifles
BH = Miniguns, LSW
NCR = LSW, FN FAL, Hunting rifles
Junktown = 10mm SMGs, Hunting rifles, 9mm mausers
HUB = Assault rifles
Boneyard = 10mm SMGs
SF = Laser rifles, Needler pistols, Assault rifles
Redding = Assault rifles, Hunting rifles, 10mm pistols
And also you could search caravan carts and sometimes found items (Like you can try search Fuel cell controller from old cars)
Items like: Caps, Weapons, Armors (Leather jackets random damaged %) and Drugs.
Edit: Please comment