Yeah the CoolBoy situation is confusing, somewhat intentionally so (in that one company ripped off the other). Formatting is inconsistent, so you might see it appearing with different variations of spaces and capitalisation even within products from the same company.
As far as I can tell, the first appearance of CoolBoy was a brand name used by Subor - it appeared on several handhelds from them, mostly export models, including their Z12 handheld Famicom, and the Z09 which used its own format of cartridges and I think was VT03 hardware. A few other Subor handhelds also used the Z09 cartridges but were mostly the same thing in different form factors.
One of the later cartridges released for the Z09 type systems was the 222+23 in 1 multicart, which would later go on to be released in regular Famicom format by a company called Fuzhou Coolboy Electronics. This cart was pretty well-known as leading the trend of high-capacity Famicom multicarts which are commonplace these days. Other releases from Fuzhou Coolboy included a 150 in 1 and a whole string of re-released Waixing games under different titles.
This, plus Waixing's close connection to Subor, Waixing and Coolboy both being based in Fuzhou, and sharing common PCB and cartridge case designs, leads me to believe Fuzhou Coolboy was either Waixing using a front company to distance themselves from their pirate multicarts, or a VERY close affiliate of Waixing.
Fuzhou Coolboy's name in Chinese is 福州酷哥电子有限公司, the relevant "Coolboy" part here is 酷哥, Ku Ge, or "cool brother".
A little while after Fuzhou Coolboy's carts became successful, Shenzhen Renshun Technology popped up with their own line of CoolBoy multicarts. I believe their first one was an 8 in 1 or something unimpressive, but they quickly copied Fuzhou Coolboy's style of high-capacity multicarts with a 198 and then a 400 in 1. In Chinese, they write their CoolBoy brand as 酷孩, Ku Hai, or "cool child". Under this name they also put out a couple handhelds like the RS-1, but I'm unsure if they really manufacture them. So this is a second CoolBoy, making very similar products to the first, but an entirely different corporate entity using a slightly different Chinese brand name.
THEN a while after that, Renshun products started using the CoolBaby name in English instead of CoolBoy. The Chinese name remained Ku Hai however. I highly suspect the reason for this is that Fuzhou Coolboy/Waixing or Subor probably had a trademark on CoolBoy and forced Renshun to stop using it (but I don't have any proof of that). Older products are still in production using CoolBoy, but newer ones use CoolBaby. I also think it's likely that many of the CoolBoy 400 in 1 multicarts on the market now are knockoffs and not actually made by Renshun, which complicates matters even further.
(There's also the "Super Cool Boy" line of multicarts from ABABsoft, which I believe are completely unrelated to the other two)
As for who's actually manufacturing Famiclones for these various companies .. I will throw my hands up in despair at this point but maybe I'll come back to it later
okay yeah and on the subject of who's manufacturing famiclones, especially handhelds... it's kind of a mess and often complicated by them all ripping each other off
There are a few groups I can at least say something about though:
- Subor (小霸王), historically, always made their own products in their factory in Zhongshan. I think they do still make things there, stuff like their 'educational' systems and maybe some other crap. HOWEVER Subor has also recently licensed its name to other companies, notably Renshun and Toycenter, who have used it on all-in-one Famiclone handhelds. Generally any modern handheld console with built-in, pirated games, bearing the 小霸王 name, was probably NOT made by Subor but just by someone who had a license for their name.
- The "PVP" group.. this one I could never properly identify. They make things like "PVP", "GB Station" and their various spinoffs (although SOME of the spinoffs/knockoffs may be made by other companies, since the line is so popular..), typically found with 3 multicarts claiming some ridiculous number of games like 9999999 in 1, the carts are always fake and only activate built-in games. Nanjing and Jncota both listed these consoles on their websites at some point or another so may have been somehow involved. I think possibly some of the designs and hardware used here were derived from Jungletac (licensed/stolen?).
- Wellminds seems to be more of a "design" operation, that is they design hardware and multicart menus for consoles, and sometimes develop their own games too. However they've also been releasing their own consoles lately which use the MOGIS or "BL" brands. Mostly these only seem to be sold in China. I'm unsure if they have their own manufacturing operation now or if they're having some other company do it.
- Renshun aka CoolBaby aka (the second) CoolBoy: I don't THINK they make their own handhelds but I could be wrong, it seems more like they contract another company/companies to actually make them to their specifications. But I don't own any of these consoles so idk. Matters are again complicated because this brand is POPULAR as hell in China which means several taobao and aliexpress sellers list unrelated consoles as being CoolBaby/Renshun products.
- "touchgameplayer" I guess is the latest company to claim some ownership of the whole PVP station thing. But the non-handheld consoles they list on their website mostly come from Trump Grand (a longstanding famiclone maker, responsible for Power Joy and a lot of DreamGear's plug n play stuff) so I suspect they may not be a "manufacturer" as such, but maybe another "design" operation that works with other manufacturers, hence them having the ability to hack their URL into so many games. Some of the handhelds on their website look identical to the ones sold by Renshun.
- Qi Sheng Long/Hamy/Feihao is a long standing manufacturer and they make all their own stuff, I don't think they make anything for any of the other Chinese companies mentioned here, but they do make a lot for export.
- Some smaller, "niche" manufacturers which DO seem to have made their own stuff, but on a relatively small scale and mostly sold in China:
- Toycenter aka Zhanglong aka Digiking made some pretty low-quality stuff, either under their own name/s or Subor's. Not sure if they're still in business.
- Xiaoshenyou or IQQUE made SUPER low quality shit and seem to be gone now
- "SY", don't have their full name to hand right now, MAYBE made their own stuff but it could have been outsourced especially later
there's probably more i could say but i'm also gonna sleep