Super Flower's factory, Jing-Hua, is pretty small. With all the orders they get from EVGA, their own retail arm, and other companies, they have no choice but to outsource production to other contractors to meet the demand - and not to just one factory.
Example: one of such factories is Shenzhen Rui Sheng Yuan Technology, which manufactures part of Super Flower's orders for products based on Golden King, Golden Green and similar designs from this series. Shenzhen Rui Sheng Zuan were also a subcontractor for former Topower and Huntkey.
I rehosted a specification PDF I once accessed from some place, take a look:
http://orionpsudb.com/application/files/6614/4282/9355/SFExportSRTC.pdf
They also use some more known companies. Not Enhance or FSP, but it does have three capital letters in its name if you look at it in the right way - and it's usually not associated with quality products at all. And the little quirks that different factories have show in the reviews sometimes - if you look at the reviews of certain lower-end products from EVGA or other brands by SF, you may notice some imperfections in things like soldering quality, with some of them pointed out by the reviewer.
Now they still perform as good as what you'd expect the platform, since it's the same design after all. Just assembled by different people, which I don't think is a big deal at all when the occasional QC slips are kept under control. Some of Super Flower's contractors don't care about the quality of their own units, but when they are ordered to make products for Super Flower, they both (the OEM and Super Flower) make sure to do their best.