At this point nobody is completely sure that Wemby will not have ongoing issues - a guy like that with a freak body size is going to have ongoing medical issues. I'm not sure if you can build your team around so many questions. Giannis also has his share of ongoing injuries. Most all bigs who are subject to knee, foot, back issues are the norm and that's what makes guys like Wilt, Russell, Duncan so special.
IF and that is a huge IF, Dallas passes on Flagg and he slips to SA - I feel a great get to that line-up IF Wemby returns healthy. Adds the scoring skills/handle that Spurs need from the wings.
I agree that Steph needs to work on his 3pt shooting and I am sure he will during this off season. It would be strange to see them trade their just named ROY away but it's a business and anything can happen