Doug Brien of Mynd and The Real Deal’s Hiten Samtani “Do you have to live in Atlanta to invest in Coca-Cola?” Doug Brien is making a point about how provincial single-family rental investing is, with people tending to buy within driving distance of where they live. That’s because the market, unlike those for stocks and bonds, is messy and opaque. Things we take for granted in debt and equities — reliable data, smooth portfolio management — are hard to come by in single-family rentals. Brien speaks from experience: He first took on the sector as co-founder and CEO of Wall Street-backed Waypoint Homes, which he built into a $3 billion,…