grimfox :
In my experience mixed component manufacturers are very common.
I don't have a problem with mixed component manufacturers. What I have issues with is using poor quality components in critical circuit locations, such as on the outputs of a flyback power supply. Those are close to 100% guaranteed to fail before anything else except possibly the battery. You can use ChengX, Su'scon, Jamicon or whatever else you want for local bypass around opamps or linear regulators but flyback power supplies will eat those as entrees.
What conversion topology is typically used for standby/5VSB and most other sub-50W power supplies? Flyback. As I have written a few times in the past, flyback converters are particularly harsh on their output caps: they receive a sharp current spike when the primary side opens and that spike contains all the energy the capacitor needs to feed the load through the remainder of the cycle plus the capacitor's ESR losses. A capacitor's life in a proper design does not get much worse than this. If you read my AR300 and SL300 PSU repairs, the first capacitor after the output diode on the 5VSB output in both were completely dead, as were all other caps powered from the 5VSB transformer's outputs.
Destroying capacitors is the flyback topology's specialty. Why is it so popular? Because flyback converters have very few parts, are very simple, very small and very cheap to make. They can even be efficient. To get a good lifespan out of them though, you need a mix of output capacitors that can take the beating.