The site below ranks players by perimeter defense, interior defense, and total defense. Not surprising to see Augustine ranked the 34th worst and Fournier the 44th worst. Oladipo is ranked the best perimeter defender, and Jonathan Isaac ranked 13th in total defense in limited minutes.
http://www.basketballanalyticsbook.com/2018/04/19/anthony-davis-rates-as-the-nbas-best-defender-in-2017-18/