Light oil, heavy oil? how close are your IQTP and you HP to the Disturbed? I would personally think about trying to get the Nano Pearl in there.  How dry does your league night get?  Is the Tropical Heat Hybrid for the last 2 or 3 frames, where a step further in, or flattening out might be just as good?

I personally right now in the bag, have:
Pursuit (Pin up)
Defiant (Pin out, Double Thumb)
Totally Defiant (Pin out, thumb kicked left 23 deg)
Versa Max (pin up)
Crown(Spare)

Each ball has a reason. 

Pursuit is good through the heads, has a late, strong break.

Defiant is weaker than the Pursuit, and uses a different part of the lane for a break, if the Pursuit gets to snappy off the back, the Defiant has a different shape, and there's usually some oil left where it makes its move.  Also, lanes 1&2 at the local center sometimes has issues carrying corner pins, and the Defiant has just the different shape to carry.

Totally Defiant This ball is very clean through the heads, and if the backends are snappy, this ball is a beast.  Started the year with this as my Primary, but the longer THS they are using this year, and seemingly inconsistent cleaning of the backends, this ball gave me a lot of head aches with 2 pins, 2-8's, and buckets.  But is a great Pearl for the right conditions.

Versa Max This ball doesn't get a lot of use, as I have been developing my deeper inside game, but when I need to play a down and in shot, this ball is great.  This ball like power, fingers straight up the back, and just let it move into the pocket.


I'm not perfect at this sport by any means, but I feel I am on the path to getting better.  It's more about execution for me right now, than not knowing how, at least that's what I currently feel.  Take from me what you want.  I would suggest having each ball in the bag be there for a reason.  Different shape hook, big enough difference in hook, different way they react on oil, dry, transition...etc.  I carry 4 strike balls, but intend on only using 1 all night.  I am/have learned to play further inside to avoid other bowlers oil, and provide for less change in my shot throughout the night.

Disturbed- just for heavy oil (which is rare in any of my leagues)  Hyroad pearl- max length with incredible back end    IQ Tour pearl - nice length with very gradual back end and Heat-even straighter than the IQ Tour. Not sure where my Nano Pearl would fit in here but it is a great ball. Need to find a place for it just not sure where.

Sounds like you need to go to the lanes with everything for practice.  stand in on spot and get a for sure what is stronger, what is weaker over all.  You should also get yourself in a spot where you know if ball "a" does this, I go to ball "b" and stand there.  if ball "a" does that, I go straight to ball "c" and stand here, so on so forth.

also, if you are looking to "thin the league herd", you need to be in a spot that you will have no regrets of I should have had that ball in the bag instead of this one, cause this one is too similar with the others.  have no regrets, if you make a choice, and it doesn't work, don't beat yourself up, just learn from it.  and also, because you choose one way, doesn't mean you can't change.

side note, if you can get find a ball that works all night, you'll be better off and just have the others with you for strange abnormalities.