do all sets have variety in their sizes?

Hi folks, I'm hoping you can help.

I've bought three sets of coins now, from different places, and having no luck. Every set of coins I get (all wooden) come with coins that are distinctly different sizes, such that I can't set them up into a uniform break.

SO, two questions:

(1) does it matter? are they meant to be uniform in size, or do all sets have variety in their sizes?

(2) if it matters, where can I get a decent (i.e. tournament quality) set of coins ??? I am based in the UK

hope you can help!

I didn't find the right solution from the Internet.

-References
-https://boardgamegeek.com/thread/1708038/help-i-cant-find-any-coins-uk

-Workforce Solution Video