I understand many of us have bad takes here and we should always "trust the corches" until they get fired (sometimes for their stubbornness). My personal hot take on Sark's decision making with regards to the two QBs is that he doesn't want to tank Quinn's career by benching him.
Quinn was the #1 QB in his recruiting class and flashed his talent several times over his career, so letting Quinn fail is not only bad for Quinn's career but also a big ding on Sark's resume. If Arch excelled in the two drives against UGA, Sark probably bites the bullet and goes with Arch for the rest of the season. But since Arch couldn't capitalize on his limited opportunity, Sark is going to ride with Quinn. Arch is not clearly better than Quinn at this juncture of his career, so the decisionto stick with Quinn is defensible and less controversial. He probably wants Quinn to succeed more badly than Thatguy.