Okay, if Dumbledore's in the middle, then I'd expect two of the Heads of Houses to either side of him. From there, could it possibly be alphabetical order by department? Or maybe, Dumbledore has his own unique schema for seating the faculty. He might have placed Doug near the middle to make introductions easy, and IIRC, Snape is the Head of Slytherin.
ETA: And while I'm thinking about it, is it possible that Trelawney's gift kicked in when she saw Doug? What would he look like to an actual sybil from the HPverse? And yes, I'm sure JKR knew exactly what she was doing when she named the Divination professor "Sybill."
ETA: And while I'm thinking about it, is it possible that Trelawney's gift kicked in when she saw Doug? What would he look like to an actual sybil from the HPverse? And yes, I'm sure JKR knew exactly what she was doing when she named the Divination professor "Sybill."