Pick Thickness

[PickaA9]

I'm creating a custom set, and I plan on picking only American locks.
I started watching this bosnian bill video on youtube for some guidance https://youtu.be/nYOTJh7NV68

Although something he said confused me and raises a few questions concerning thickness when picking mainly American locks.

At https://youtu.be/nYOTJh7NV68?t=267 he describes a "small" half diamond being the most useful sizing, this raises some questions.

1. When he mentioned the half diamond what did he mean by "Small" (what thickness is this?)
2. Mainly my current selected set consists of 0.025ths" hooks (what other thicknesses do I need besides 0.025ths, to pick the majority of American locks?)

[Kaesekopf]

Often times 25 thousandths is too thick to maneuver around the warding in the keyway. 19 thousandths fits many keyways in North America. There are people making, or starting to make picks in 17 thousandths and 15 thousandths for tricky keyways.

As far as half diamonds go, I don't much like them. I'd rather hooks in various sizes, so I can lift high set pins without disturbing neighbours more easily. I can't remember the last time I tried to find a serious use for a hook. My own biased opinion of course

-Kaesekopf (Cheesehead)