Looking at the balls you named, there are some problems that i see. For one, there is definitely overlap. The VG and Rogue Cell are pretty similar as far as oil handling and strength, and the 2D and One pearl are close to each other as well.
Also, you really don't have anything on the weaker/lighter oil side of things. The One Pearl is the weakest you named, and even that's a strong pearl. You'd definitely need something weaker than that.
So, since you said you'd have to keep the One, maybe run something like this:
-Virtual or Rogue
-One Pearl
-Pluto, Hy-road, or Furious
-Mars or Neptune
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Formerly Chocolate Milk.