>>108587743They're like Mario and Luigi crossed with Jay and Silent Bob. The focus is on the shorter one in red, the one who talks the most. Not the taller, green guy, the one who never says a word. It's the red one, the voiced one, who comes up with the plans and does all the verbal communication and stuff while the other guy just goes along with it and assists in the action. That's just how that kind of dynamic is.
It's the kind of dynamic where the focus is so heavily placed on one, that if you separate them, at first you'd think Phineas would be just fine by himself with not much different, while Ferb on his own is a completely separate scenario.
Like... what would happen if Phineas and Ferb got separated, where Phineas was off on his own by himself, while Ferb was with Isabella, Buford and Baljeet and whomever else without his loud idea-guy brother as the leader?