How do you separate Villanova and Virginia? Not easily.
They're the top two teams in the country by whatever metric you pick, they both have lost only once, on the road to good teams – Virginia at West Virginia, Villanova at Butler – and they both have an impeccable record against the best teams they have played (Villanova is 13-1 in KenPom A/B games, Virginia is 11-1). Virginia's win at Duke is better than Villanova's best win and Virginia's loss is better than Villanova's loss, but Villanova has played a tougher schedule overall which earned it a couple more good wins.