the book i saw (which was as thick as a bible, and i mean huge)
That's the Taiwan Bicycle Guide. It's got stuff from pretty much every Taiwanese factory in it.
Here's how it works. You are a bike company. You have designed a range of bikes, but for whatever reason (cost, volumes) you either can't or don't wish to actually build the frames yourself. So you go to Taiwan and find a factory that can make what you want. You might do this through TaiwanBG, or some other agent. You get some samples made, and when you're happy, you order a few thousand frames.
In earlier days there was a not-insignificant risk that your frame design would then find its way into the Taiwan Bicycle Guide as an off-the-peg option that people who couldn't be bothered to design their own stuff could order themselves. These days that doesn't happen so much, partly because the bike companies are a bit more canny with contracts, partly because it'd be harder to get away with because frames are pretty distincitive these days, partly because some companies actually own the tooling that lives in someone else's factory, partly because in some cases the factory has a large stake in the company and it'd be like shooting themselves in the foot
The upshot of all this is that, while it's entirely possible that Kona and Marin frames have, at some time, been made in the same factory, that doesn't mean that Kona and Marin are in any way related beyond happening to have contracted their manufacturing out to the same factory. This is inevitable, because there are more brands than factories. It's also often the case that different frames from the same brand are made in different factories - some factories specialise in different materials, some may be cheaper but not quite as high quality, so they do the low-end frames and the posh stuff is done up the road.
It's all quite complicated, really
