functional design vs aesthetic design(visual brand languae

Okay, understanding that the two need to be married and work together, if you had two designers and each one had one of the responsibility

designer one - in-charge of developing functional design

designer two - in-charge of developing aesthetic design

What responsibility would you place under each designer.

Also looking to see if there is a standard definition for the two within our industry

I would not have a “vs”, and I would not have two people in charge of developing separate aspects of the industrial design. In my opinion, it all needs to be thought of as one. Not two things married together, one thing.