The talent gap isn't that far to answer the posters original question. In fact I would say they are as close as close can be in terms of talent. Lawson IMHO if he had stayed healthy this season would be a lottery pick right now. His ankle was even bothering him in the Louisville and Kansas games during the tourney.
I think reality is that both these guys are looking for Tyronn Lue/Travis Best/Kyle Lowry type careers where they can be productive but never a starting lead guard.
Their success will depend on the team that drafts them...I don't like Augustin on the break and find Lawson unsatisfactory in the half court.