The workouts should be huge for Miller. If he shows that his athleticism is back or coming back, then he could potentially be a late lottery selection. He's just too skilled, tall and highly thought of in high school not to be a dark horse late lottery candidate if he shows well at workouts. I thought a scout quoted in David Aldridge's draft series had a really quote about him, saying that the leg Miller tore his ACL looked like it atrophied, questioning his rehab. If that was the one of the reasons why his athleticism looked so diminished, then perhaps there's hope that Miller will be able to fully recover with professional rehab.
Regarding Draymond, I don't think he's a 4 except for rare matchups. He looked about Pierce's size, in the 6'6'-6'7 range with long arms but not quite the 6'8 to be a full time undersized PF.