How do you know that the difference in growth response would be MINIMAL...you don't! This is why I have experimented with this possibility endless times, and proven time and time again how you can get a significant growth response in a SECTION of a multi-headed muscle, causing the appearence of reshaping.
It is a contradiction to believe that you can "stress" one head of a tricep over another, but not believe that you are causing more growth in that area.
But you know what. I'm getting tired of arguing with you about this. Don't listen...you are only hurting your own progress, not mine or anyone elses....