I guess one could argue that both Hill and Rudy have a history of good d which gives them a pass.
The 26 games they have played together? Exum had 41 games starting and playing with Rudy his rookie year and they produced a higher level of defense during that time. There are also some statistics that point to Exum playing better defense this year over Hill and that Exum is better at defending the three point line. Dante holds players to 33.7% from 3 point line from players who normally shoot 36.1% (net -2.4) whereas Hill holds players to 39.6% on players that normally shoot 36% (net +3.6.) Which makes Hill our worst 3 point line defender of any of our perimeter players.
https://stats.nba.com/players/defen... Season&TeamID=1610612762&sort=FG3_PCT&dir=-1
https://stats.nba.com/players/defen...n&TeamID=1610612762&sort=PCT_PLUSMINUS&dir=-1
On those stats our best defensive lineup would be Exum, Burks, Hayward, JJ and Gobert.