You've got the plan wrong, the idea isn't for any team to draft and hold on to Wemby's brother until he reaches free agency, more like drafting him, building a relationship, being "extra nice and accommodating", trying to generate good will. His size and athletic profile would make him blend in much more seamlessly than Bronny (6'1" combo guards who can't shoot are dime a dozen), I don't see why he'd be a distraction.
If he proves a real NBA player then great, it's a great pick on its own. If not, you do right by him, send him wherever he wants. Then when Wemby's free agency comes close, you have even a little bit of an edge, an inside track. Big market teams have gone much farther than that in the past (Clippers with Kawhi, NY with Brunson, etc). It costs them very little, may end up a worthwhile investment on its own (if he pans out) and if not, you've built bridges that may help you in 4 or 5 years. We've seen schemes 100x more absurd than this come to fruition.