What makes a company a USA breeder? The strains were originally bred AND seeds are grown in AND sold from the US? The strains were originally 'bred' or developed in the US? All, most or some seeds grown in US? Owner(s) in US? Seeds are sold and shipped from US? US address at Web site, social media, etc.?
What if Mephisto had continued to do their breeding in the UK and contracted for seeds to be grown in and sold from Spain, would they be UK or Spanish breeders, or commonly labeled as both? What if a US company or grower made the strain(s), another US company or grower makes the seeds, and another sells for them - which party or are all considered USA breeders? [In the real world, professionally, I am often forced to assign a single location for companies, and it often comes down to arbitrary decisions. Since this is often for publication, I generally make the safest choice, what I presume most other experts would pick, and avoid having any set guidelines].
And what about individuals (vs. companies) being breeders? None have been mentioned so far.