They should be roughly the same thing.

If they aren't, then one isn't good at evaluating what a team has "done." The degree to which a team dominates an inferior team is both predictive of how they'd do against a better team and reflects how good that team is. But it's appropriate to give the edge to the team that has won more games against stronger opponents because it eliminated doubt as to its ability to compete at that level.

But generally, gauging dominance that leads one to predict an Alabama victory over ND is a reflection of what a team has done.