Alright, I'll preface this with: The following is merely my opinion, thereby giving you an immediate 'out'.
I'm sorry but I cannot see how you miss the similarities between Sire, Sunday, and Conspire. Even my math teacher, left-brained girlfriend can see the likeness in not only style but flat-out design.
Let me get to the point- paintball is still a small market, and in this small market when you see a product from a new company that's exactly like an existing one from an older one it's hard not to view it as a rip-off. Granted, when you see stuff like the old 32 Degrees stainless steel barrels obviously ripping off the DYE SS of the time, you see someone as trying to snatch some money off the back of the popular product with perhaps a lower-grade version in the same packaging. I'm not saying Sunday or Conspire are lower-grade, the difference when it comes to something like clothing or artwork is originality. If someone doesn't mind paying a little less for a little less quality when they're trying to get a stylish barrel is something different than someone buying a shirt, or, essentially artwork.
When someone starts pumping out artwork and it becomes popular, then they start making money, THEN someone else sets up shop right beside them making the exact same thing, that's the short version of where and how vendor #2 becomes unoriginal. As I said, it isn't like any of these companies are beside each other on a rack at Macy's, I'm talking the small-scene of paintball here.
Coming from a long line of artists and being a freelance illustrator, I suppose stuff like this gets to me more than it would the regular paintballer. That's why I originally wanted to ask what was up with Sunday, Sire, and Conspire being all on one site, I didn't know if Conspire was an off-shoot of Sire in the UK or what (and when you said you didn't name your company Sire UK, I smiled and thought, "He read my mind").
I'll go ahead and admit it's none of my business as it obviously doesn't personally affect me, but with all these new 'clothing' companies popping up everywhere, all I ask is for them to at least be original. Sire and Bunker King are the daddies. That's only two companies to not have to resemble. If I made a Boomstick and milled 'Five Finger Bullet' into the side, people would still see a Boomstick. Working freelance I know all about bending to the will of your client, making up stuff you wouldn't personally like, but if I sacked up and started my own clothing line, especially in the niche of paintball, I'd want to be unique... although I'll bet I could get a few bucks with my Bunker Queen line.