Let's see:
The zodiac theory states there's twelve strong Marines each with an epithet created by combining a color and a zodiac animal. If we subtract Kuzan, and either Borsalino/Issho, we are left with 10 strong Marines for 10 Straw Hats.
If we add Imu to the ranks of the Holy Knights, we have 10 vs 10 as well.
If we subtract Kuzan from the Blackbeard Pirates, we are left with 10 primary members.
Coincidence?