I have a suspicion, though I will never be able to confirm it, that the same factories are making parts and pieces for a lot of these brands. That's how it works in the vast majority of other industries; you have the "basic" factories that are the biggest and turnout the most quantity, so they can do things the cheapest.
As for the HT, I will mention that CKF tends not to make any kind of HRC promises, so there's a distinct possibility they're treating to a jumble of different values with an inconsistent protocol.
I do have to be real though, I never carried any of my CKFs (don't own one currently), as a user, so I'm genuinely just speculating without even the aid of anecdotal evidence.