hmmmmmmmmmmmmmmmmmmm. not sure if im qualified to answer this question, i could never figure it out in all my years
an interesting question for sure.............
why do barbell bench when you can dumbel press
why do barbeell curl when you can dumbel curl
why do barbel military press when you can do with dumbel
why do easy bar skull crusher/french curl when you can do hammer grip dumbel skul crusher
?
symmetrical development
?