I think overall, you have a pretty good foundation. The only possible gaps I can find would be having a solid to compliment the CrossRoad and then possibly a hybrid to compliment the Nail. The reason I think this is because tournament shots can be different from what you're used to and having mostly skid/snap is not always the best option.
The CrossRoad drilled weaker will work on most medium volumes, but medium-heavy patterns are not the strongest suit for this ball. That's the gap I see between that and the HRR. In this case, I could see you going with a Roto Grip Disturbed to fill the gap nicely. That ball will handle medium-heavy volume well and rolls earlier in the mids to give you good predictability. Plus, you can play straighter or move in as needed. This fills the gap for the fresh if the HRR is too much but the CrossRoad is not enough.
The other spot I can see you adding 1 other ball is on the medium-light patterns. The Nail is a good choice for drier conditions and the pearl cover will give you good backend. On the fresh with skid/snap, you'll see some over/under in some cases. This is where I would see you going with something such as the Roto Grip Wrecker or the Storm Frantic. Another option if you go with a solid cover would be
Either of these balls have good hybrid covers that allow for easy length, good midlane read, and still give you a good backend and would be a great step down from the CrossRoad. More importantly, you would not have to make as much of a move stepping down to these as compared to CrossRoad to Nail. Basically you're able to keep more similar lines and angles, which is important.
From there, I would step down to the Nail since that will give you the most skid/snap when the lanes really start to become torched.
Other possible ideas include:
Heavy oil- Roto Grip Defiant or the new Storm Sync. These balls will handle as much as or more oil than the HRR. Both of these have great covers/cores and could also fit you well. I haven't thrown a Sync, but have a Defiant. That ball has proven itself in heavier oil patterns that I see in houses around here.
Light Oil- The Roto Grip Shatter or the Storm Tropical Heat Pearl can easily work here also. The Neutron Core on the Shatter is tough to beat with how good it is though.
With that being said, here is what I would do:
Heavy oil- DV8 Hell Raiser Revenge, Roto Grip Defiant, or Storm Sync
Medium/heavy- Roto Grip Disturbed
Medium- Storm Cross Road
Medium/light- Roto Grip Wrecker or Storm Frantic
Light- Hammer Nail Smoke and Fire or Roto Grip Shatter
Hope this helps and good luck.
