How to determine how many printer patches to use in the test charts you print.
This a topic that can generate a lot of discussion and there's a number of schools of thought on how to determine an exact "ideal" patch count.
We typically would recommend a minimum of 400 patches per channel for a quality printer profile, so if you were printing using an RGB printer (which would describe almost all inkjet printers, when using the printer driver), that would mean a minimum of 1200 patches.
We've found that going much beyond the 2033 patch count (the default patch count in the Advanced mode) gets into the area of diminishing returns pretty quickly. You won't gain significant improvement in gamut volume and could actually reduce the profile's quality if you go too high. We would typically suggest you could get a better result by measuring a target more than one time in the Advanced mode, saving each measurement separately, and then letting the i1Profiler software average them for you. That would tend to smooth out any irregularities in individual patch measurements. if you're doing hand measurements using an i1PRO2, it can be possible to introduce some unintentional variation in measurement if doing a single set of readings.
The reason you've read that "too many patches are overkill" is due to the fact that i1Profiler permits up to 6000 patches, and many end users feel that they need to use that overly large patch count. That would simply be unnecessary for any Epson, Canon or HP inkjet printer.