Your friend is giving you some good advice. 10 might be too many or too few depending on what else you can do as far as "tricks" are concerned. The more extra things you can do to give you different looks will determine how much stuff to carry and drill up.

Think about the patterns also. You have 2 of them at 35 and 37' respectively. Now put those on wood, HPL, and Brunswick Pro-Anvilane and you could concievably have three different ways to play each of those patterns. Now if you can get right and get the ball to ignore the front thru either a low tilt/rotation release or picking up your speed/tempo, you have a way to combat higher friction surfaces like wood or wood w/guardian heads.

This can be the same on the 2 longer patterns that are 41 and 43' feet. Being able to slow down your ball speed/tempo can really help you on the Shark and Scorpion once the oil has carried down (transition). Scorpion on wood can get hooking rather quickly in the 15-11 area of the lane. A logical move is to get more left and swing the ball to the friction. The patterns can be flatter than league patterns and you can get 2-8-10 or a greek church reaction doing this. This is a place where having a particle pearl that is laid out to not change direction quickly can help for awhile until they get flat out wide open late in the block.

What I have overheard and spoke to a few guys in our region is to try to lay out balls by response to friction. I would try to get a good understanding of Mo's Dual Angle technique. Also try to have a couple of balls that are laid out to not make strong direction changes especially a pearl particle in this kind of layout. Pearl particles can be a great bail-out ball during transitions on the lane.

As far as what balls in your favorites I seen out there most of this last summer:
Storm: T-Road solids and pearls, Spit and Sure Fires, still see guys using Fired-Ups and Pyros, and Special and regular Agents.
Hammer: Solid Widows, Blue and Cherry Vibes, and occasional Toxics/Dooms.
Brunswick: Total Infernos, Sidewinders, Red and Vapor Zones.

Disclaimor: Strictly my opinions and not a guarantee to success.
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Mike Craig-Columbus, OH

I tend to agree with Jeff Carter.  

You have to keep in mind that coverstock and individule ball characterisitics are the most important part of building an arsenal, not the drill layouts.

You could use the same type of layout on most of your equipment and get many different types of reactions from the different balls.  Here's a generic way to put it.  Use the same layout on all your equipment and let the covers and cores separate the reactions.  This example is just for you to get the gist of what i'm saying.