I am with CharlesT - assuming that the two balls are identical, even the same coverstock with just a solid and pearl reactive version, both with the same surface prep, they'd IMHO be too close if you drill them the same.
If they should be a complementary couple, I'd drill the solid one stronger, for earlier roll and the pearl for more length and flip, just as CharlesT suggests. I'd also keep the pearl polished, and take the shine off of the solid one. This will be a good, more arcing ball for oilier shots, while the pearl will be a option for late games, light oil and the THS one might encounter.
For reference for such a combo, check out Brunswick's current BVP Rampage and Wizard - basically the same ball, but with differing surfaces and a proper setup, this is a very versatile combo that will cover anything but the most extreme conditions.
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DizzyFugu - Reporting from Germany
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