How naïve that a Chinese manufacturer would think they can sell D38999 connectors. As it is Amphenol is not looked on very favourably these days because they were found to be using components in their connectors made in China although I think there is a little bit too much hype over this as the emphasis should be on quality control of the components and not where they are made. P.E.I. Genesis in fact is now looking to add Souriau connectors to its range as the Americans are very funny about where the parts for their D38999 connectors are made although personally the connectors I have seen from America are total and utter shit.
I use D38999 connectors on a daily basis and have become something of an anorak. In theory any connector shell can be used with a PCB pin. The difficulty you might find is that if you are educated in the standard military part numbers for the connector range you probably already know that PCB pins are not covered in the codes. For these you have to resort to manufacturer specific codes. It's a shame the American military who think themselves so clever can't keep up with the pace of technology. I find myself using the souriau manufacturer part numbers so that I can create a part numbers for connectors with PCB pins. When it comes to PCB pins the other thing you need to be careful about is the fact that each manufacturers pin could be different because they are not covered by the military standard. It's probably not recommended to put pins from one manufacturer into connector bodies of another manufacturer but I can't really see what the problem would be because the connector bodies are made to a standard so the pins must to a degree conform to that standard so that they can fit the connector body. But you will get things like shoulders being in different places. I recently did an ECU design where the cover coming down over the connectors and then screwing to the rest of the ECU body relied on knowing the exact distance from the front flange to the PCB shoulder on the pin and I accurately 3D model all parts and things came out fine however if I were to use connector shells of a different manufacturer and PCB pins of a different manufacturer the design would completely change as there was quite a degree of variation allowed in the shell castings in the official D38999 spec which you can download a copy of from the Internet.
If you are sourcing D38999 connectors I can strongly recommend servo connectors as they are much faster at quoting and supplying and often cheaper than P.E.I. Genesis with whom I gave up in total frustration as they seemed incapable of quoting quite often and have this fad for giving everything their own part number so you end up with three layers of part number, P.E.I. Genesis part number, the manufacturers part number, and the military part number. I began to have problems where I was asking the connectors they had not made up total yet so they made up codes ad hoc and then when we tried to order those parts again they said they could not recognise the part number. To be fair this was on 5015 reverse bayonet connectors where there is no standard part numbering system although most people tend to go by the Canon part numbers which are the manufacturer P.E.I. Genesis are franchised to sell. But their sales rep didn't seem to be that fazed by the problem and is pretty much ineffective.