No way. Del Potro's defence is the best BY FAR, that's why his slam count is 1 and the others 0 because defence these days is the number one asset required at the top of the game.
Berdych is a bit of a poor man's Safin. Some variety, great backhand but not at Safin's level and a forehand as good as Safin's.
Soderling is a flat ballstriker. A basher at times too, but his victory over Nadal was down to patient construction, moving him around side to side and then coming forward to finish the short ball. When he plays like that, he's one fearsome opponent.
Del Potro I find to be a more high percentage 'basher' as his shots are less 'risky' than the other two and often tend to find the middle of the court a la pusher-ish until he gets a short ball from his opponent. That's why I've never warmed to his style as I think it's quite uni-dimensional. The other two guys have more of a 'point construction' about them and that's why I prefer them.
You could add Tsonga as well given he hits hard at times too, but his backhand is pretty inconsistent but his net game is streets ahead of the others.
Talent wise it's hard to pick a winner.