You seem to have the right idea with your listing of pieces per category of hvy/med/lt oil...
With all due respect (and we're probably talking very general here), in regards to some of your observations, I would still invite you not to be set in allocating a set ball-type to a set oil category (again I'm respectfully challenging your thought process in a friendly/professional manner)... When getting into those balls that are below heavy-oil performance but above light oil performance, you can get a ton of range moreso than what the price-point or marketing info dictates.
For instance, the Marvel P (used by Haugen/Fagan on HEAVY oil) if you watched the shows, on the long patterns, Fagan and Duke both tried using the Disturbed (which for generic purposes "hooks" more than say the Marvel P, but Fagan and Duke both started to see the Disturb "puke" as the pattern oil migrated). A ball like the Marvel P can often be used in HEAVY oil over even a Defiant Soul or Disturbed.
I would offer; build your arsenal around "medium/performance" level pieces like; solid symmetrics with med/high rg's, pearls w/low(er) rg's, and performance hybrids. Mix in a combo of your fav layouts or even pin downs (similar to what Fagan and other tour guys do with low rg symmetric pearls).
I'm no tour guy BUT having worked for the late Tony Reyes and hanging around at some of the stops I've learned to mix-n-match my arsenal around those MP's, IQ's, Roads, Outlaws, Disturbs, Daggers, Wreckers, etc...