Hub story: I was thinking of having a lot of SuperBoost rear hubs manufactured. I contacted many "hub manufacturers" on Alibaba and discussed the hubs I wanted manufactured..
1. I discovered that there are really only 3 companies in China that make 90% of the freehub bodies. I could select a "modular style" free hub that the hub designer would input the proper interface into the hub to fit the style I select. (Each style will let you also interchange between HG, MS SRAM, Campy.)
2. Almost all the hubs are CNC machined from Aluminum round stock. Many of the companies that design/manufacture/assemble/build wheels have access to common databases. All they have to do is modify a design from common proven hub design to meet their specific specification. (Hubs are a commodity these days.)
3. Very few hub bodies fail. What you have to watch out for is the hub machining and bearing fit into the hub, the brand/quality/class of bearings they install in the hub. (All cost driven) and that the freehub/cassette body is one that is of good quality.
A lot of the stores/companies claim they manufacture and engineer their components themselves, but as I understand it, many of these companies have common ties to each other, common machine shops and source parts back and forth between each other. China is a communist country, and the government has set up a system based more on cooperation between companies rather than by individual competing businesses.
I've found too that many smaller manufacturers in China are held by larger holding companies. These holding companies in turn are held by even larger companies, eventually rolling up to some sort of government backed entity. Its one way they can outfit smaller companies with the resources they need (like manufacturing equipment.)
Based on all of the above, when they say they make their hubs "inhouse", this means to me that they purchase the freehub bodies, axles, bearings, and other hub parts, and that they may have modified an existing hub design, and farm out the fabrication of the hub to an affiliated CNC and finish shop. All they do is assemble the hub into a finished assembly.
Thus, it is difficult to assess the quality of the hub set they are selling.
I've been using Chinese "no-barnd" hubs for years, and have only had issues with the bearing on one front hub.
I always ask them the specific brand of bearings they use, and who's freehub they are using. I also ask to see the machining specification of the hub where the bearing are fit into the hub body, and what quality control they have in place to be sure the bearing fit is correct. (Sometime it takes weeks before I am satisfied that the hub is actually being properly machined to the specification required for proper bearing fit.) I have also purchased a hub knowing I don't like the bearing brand they use and I have replaced the bearings myself to a better bearing once I receive the hubs.