Yes it's definitely the right approach for Rafa - he's not won a hard court title since 2010 and hasn't won a hard court Masters since 2009 so most of his points come from this part of the year. It does tend to leave his energy sapped for the latter part of the year, but it's worth it in terms of his ranking.
Is it, though?
Look at this way: Does he play a lot of clay tournaments because he's less successful on the hard.
Or is he less successful on the hard because he plays a lot of clay tournaments (and burns himself out)?
Maybe if he sat out MC (pfft like he will with his record there) or Madrid he's have a big more energy in the second half of the season and will have some more success there.
I don't think he really cares about the Masters though, bar one or two. It's only the clay he cares about, be it for his reputation or probably because it's his favourite surface. I don't know. But certainly he will have to give his schedule real thought in the future if Djokovic ever knocks him off his Roland Garros perch.