You might be underselling Neilson.
i believe i was the first here to offer a first hand eyewitness report on Corbin Kaufusi and suggested he would be in the NBA discussion. This was before anyone suggested he was joining the basketball team.
So Corbin has NBA strength, size, quickness, speed, hops, passion, and motor. What he doesn't yet have, certainly compared to Neilson, is knowledge.
I see where you rank Nixon ahead of Neilson, and it would surprise me greatly if that turns into reality this season. Neilson is a proven defender, and an unknown excellent 3 point shooter. So it would not surprise me to see Neilson and Austin starting in November.
But we will hear increasingly of Kaufusi's NBA potential as we get deeper into the season.