As I see it, while you could build pretty respectable arsenals out of any of the series that Track has right now, they don't cover the same spectrum of conditions.  There's nothing in the Classic line that will handle the oil of the GP2 and there's nothing in the HP Asymmetric that will work quite like the Desert Heat.  

The Slash is for heavy oil but it doesn't compare to something like the GP2 or D1.  Likewise, an Xception is supposedly for medium-light oil but it doesn't have nearly the same reaction as the Heat, also for medium-light oil.

So yeah, it looks like there are gaps within a series that would best be covered by other balls not in that series.  So in that sense, it would be beneficial to mix-and-match.  But a reasonably small aresenal could be made out of any single series if so desired.  That's what's so great about the current lineup.

SH

You could build a semi complete arsenal with any of the series that Track offers. However, you are better off mixing and matching so that you have the versatility to cover all lane conditions and are able to see what the other lines are really made of. The high performance lines are great, but the mid price stuff gives you high performance at half the cost.

Not to mention, you wont get a "true oiler" without the GP2 and you wont get a "true dry lane ball" without the Desert Heat. Therefore, if you want a complete arsenal, you should mix and match.
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