I'm unsure, as I've read both camps. How much importance do you put on muscle strength balance?
For preventing injury, many camps claim that you need body balance. Some only push towards opposing muscle groups like abs/back, others for the left right balance.
Yet ive seen some great write-ups on evolutionary design and things like our shoulders being designed for throwing and most people being mono-dextrous leaves the body misbalanced left to right because of use.
Personally the only strong variant I notice on myself is my forearms. They are corded and no fat yet left one is 12" circumference and right is 13", a large difference in strength as well.
Is this evolutionarily beneficial or should I be working my left till it's caught up to prevent injury?