I just purchased some weedless hooks. I ordered 1/0, 2/0 & 3/0 hooks. The 1/0 are actually #1 in size and the 2/0 are #2 in size. The 3/0 are the only ones that are actually 3/0 when I compare them to the other ones I have. Have you noticed the sizes of hooks can vary between the hooks made here and the ones from Japan?

I'm putting together an in-house stash of all the hooks sizes that I mainly use.

To the best of my knowledge, there are no industry standards for hook sizes.

I just purchased some weedless hooks. I ordered 1/0, 2/0 & 3/0 hooks. The 1/0 are actually #1 in size and the 2/0 are #2 in size. The 3/0 are the only ones that are actually 3/0 when I compare them to the other ones I have. Have you noticed the sizes of hooks can vary between the hooks made here and the ones from Japan?

I'm putting together an in-house stash of all the hooks sizes that I mainly use.

 

Correct. One brand 1/0 is another brand's 1, or such.

 

I bought some size 2 Hayabusa weedless hooks from TW and man were they smaller than I expected.

I might be in the minority, but I like the bass pro shops XPS hooks, as long as you keep them sharp, the price is hard to beat, and the fish don't seem to notice that it's not a gamigatzu or however you spell it that pulled them in.

There isn't a standard, period.  The sizing is determined by the measure of gap from point to shank.  That said, the size should be uniform by brand and style, which in your instance seems very, very inconsistent.  Having a 1/0 equal a size 1 and a 2/0 equal a size 2 in the same make is completely off.  If anything, the 1/0 should be comparable to a 1 or 2, and the 2/0 should be a 1/0 or size 1.  Having it drop from 2/0 to a 2 is three entire size drops, and from any manufacturer th st is unacceptable.

Case in point, the VMC flipping hook in a 4/0 is equal to a 2/0 Gamakatsu heavy cover worm hook.  Yet the 3/0, 2/0, 1/0 sizes are all relative to the 4/0.

You'll just have to play around with them and see how they fit the bait you are using.