Absolutely he could. There's literally NO DEFENDER over by third base. If he works on it and gets better he could absolutely do better than 1 in 5.
Here's an excerpt from an article I posted before on this topic:
The undisputed king of bunting to beat the shift is Carlos Pena. Since 2008, with nobody on, Pena has attempted a bunt 65 times. He?s bunted the ball fair 33 times, and he?s reached base 23 times. Even with practice, Pena?s right around a 50/50 fair/not-fair rate, but he?s turned better than a third of his attempts into bases. We find Jay Bruce at 30 attempts, with nine fair and five successful. Brian McCann also has 30 attempts, with eight fair and six successful. What?s clear is that bunting against the shift isn?t automatic. What?s also clear is that it?s worked often, and that these hitters could do better if they just practiced their bunting more.
Source: http://www.fangraphs.com/blogs/more-about-bunting-and-beating-the-shift/
Okay so 3 guys were somewhat okay. I'm curious about Pena, how many times in the 23 did he score? Because at the end of the day if a power guy bunts for a base hit but doesn't score what's the point?