So bodybuilders can get a bad rap for only being concerned with aesthetics, and not being very functional, and strongman, can get the reputation of not maximizing muscle growth.
Personally, I think you should do both!
With my style of training, I incorporate powerlifting and strongman exercises, but I’m personally a bodybuilder. There are benefits of every style of training and every sport and you should always try to incorporate them into your training.
In theory, a strongman should beat a bodybuilder in functional lifting exercises, but this match up between these two beasts might put a wench in that theory.