Find some brothers to aid him in his quest.

While Mutants may be strong humans are still dangerous in large numbers. If Big boy wants to subjugate all of humanity he will need help.

Big boy remembers he saw the road in front of him that runs east to west and far off in the distance he saw what looked like rusty Corvegas stacked on top of each other. The corvgas seem promising as he knows Super Mutants will often make forts out of scrap, but there's always the off chance that it's a raiders hideout and that would be incredibly dangerous to take alone. If he follows the road he's sure to find some brothers eventually but who knows how active humans are in the area.