Not really. This year, Ferrer's only advantage over Del Potro, seeding-wise, has been from the fourth round onwards, which is not really 'scrub' territory anyway. In round one to three, they are just as likely as eachother to draw the same 'scrub', which is illustrates my point. Ferrer, still manages to get past the early rounds in almost every event he plays. In contrast, Del Potro's pass rate is quite a lot lower. Expect this point of mine to be profoundly demonstrated during the clay season as well.
And also, although it's true Ferrer is not playing as good as last year, his season so far easily exceeds Del Potro's. 2 titles, an AMS and a 500 final and a slam semi vs. Delpo's 1 500 title and 1 AMS final. No contest.
Also, the only non top 4 players Ferrer lost to are Anderson and Davydenko, which is no shame at all. While Del Potro lost to Chardy, Kamke and Nieminen. The last time Ferrer lost in a slam to a player ranked as low as Chardy was when he himself was outside the top 10.