In my opinion it is best to first decide what your objective is, then you can figure out how to achieve that objective. For example, if your objective is to have a very high CRI, that guides you towards having more than just cool and warm white LEDs. Or if you want to make your red plants, and red/blue fish look very red and red/blue, that guides to towards having supplemental red and blue LEDs. But, if you just want a light that will grow plants well, look good, and possibly let you simulate sunrise and sunset, you might want just cool and warm white LEDs, but on two dimmable drivers. If you want maximum shimmer, you will want fewer, but brighter LEDs, or a few separated pendants. If your goal is to minimize the variation in PAR throughout the tank, you would want to spread out the LEDs uniformly over the whole top of the tank. But, this also minimizes the shimmer.
So, I suggest backing up a step, then after you have a clear goal, we can discuss how best to meet that goal.