I don't think Lombo's draft slot has a ton to do with it. For me, it's his walk rate. I doubt he's going to hit .310 or .320 in the bigs because it's so rare. If he's only going to hit .270 or so, his OBP could be in the .310 or .320 range. That's not very good, especially when he doesn't bring a ton of power.
Maybe he proves me and the rest of hte haters wrong and can maintain the .300+ batting average.