I see one view of the cartoon is here: https://www.nytimes.com/2019/03/26/art…-of-athens.html
and indeed the area you are pointing to is different:
As is the chubby wreathed figure:
My first impression is that these differences help your thesis, but that's only a first thought based on thinking that the preliminary sketch appears to be a generic set of onlookers with a man whose head is twisted as if he is paying particular attention or is otherwise an inferior student. On the other hand the finished product appears to be a dead ringer for Epicurus with much different head position and facial expression. I don't think you would insert someone strong like that (complete with philosopher beard) unless you wanted to feature a particularly important person.
If we could get a more clear view of that twisted head figure we might be able to learn more.
Also, the forerunner of the wreathed figure looks nothing like a Greek philosopher at all (nor does the current wreathed figure.)