For some perspective on just what Roy is doing: Alex O'Connell, Marques Bolden and Javin DeLaurier- the three guys who saw increased playing time and/or usage in Zion's absence- were all higher-ranked recruits than everyone on the UNC roster other than their two freshmen and I think one of them was lower than Seventh Woods.
Unrelated: Tre Jones is an absolutely incredible defender. Although it didn't look like it last night, Coby White has been UNC's second-best and most important player all season. Jones had him so shook that Roy benched White for a good chunk of the second half.