An all-around good guy with a big love for television shows and a heart to match, Michael Sullivan, also known as "TV" or "Sully," has a name that is as Irish as his red hair. All of that is a deliberate choice on Gaines's part. We're supposed to understand, right from the very beginning, that Sully isn't from around Louisiana—or at least from around the parts where all of the other characters we meet hang out.
Even more than Lou Dimes—who works over in Baton Rouge but has a very intimate knowledge of the area in and around Marshall Plantation—Sully is an outsider. In fact, even though we never find out exactly where he's from, it's pretty clear that he isn't even from the South. Still, even if he is an outsider, Gaines sets up Sully to do some important work. After all, it's a safe bet that we're all outsiders, too, working hard to make sense of everything Gaines is telling and showing us in A Gathering of Old Men. Because Sully is an outsider, too, we identify with him because it's something we have in common with that character. And that's no coincidence, because it's through Sully that we get shown some really important stuff, like the whole exchange that takes place between Fix and Gil, and all of the foul nastiness that is Luke Will.
But wait, there's more. You've also got to think about how Gaines plays with perspective in the novel. When we're hanging out with the Black community at Mathu's place, we get the perspective of members of that community. This brings us closer to those characters and makes them easier to understand and relate to. We meet the Boutans and Luke Will through Sully because Gaines wants to make sure he keeps us at a distance from these toxic characters so we can see them in all of their horrible awfulness.