mixing power cords?

I use a mishmash myself, Oyaide, Gutwire and PS Audio. I bought 2 previous generation PS Statement PCs from Hong Kong for about $200 each. I have heard about counterfeits but they certainly look genuine, ground plug unscrews, logo accurate etc. I use them with my BPT boxes. I would not worry about using different ones, tests I have seen indicate that different ones are better in different applications anyway.

uniformity from a single manufacturer will almost always give better results in my experience.I used to mix and match before,but once you have tried fr single manufacturers ;you will never go back

Add different ingredients to achieve a better mix.

Even if you use all one brand, you probably won't be using the same model all over.

I use a Python VX to feed my Duet which supplies my mid fi & rotating gear. I use an Elrod Sig III to feed my Haley which in turn gives juice to a PC, multi ch amp and DAC.

I like Voodoo, Elrod, and shunyata in no real order. The Taipan Helix works best IMO on tube gear, the VX needs to be on rotating stuff or overtly bright sounding things. The Elrod I think I like the best but the Voodoo I have the most of and they are a good value & performing cable.

A bit mo' info on what you are seeking to achieve with this addition would be more helpful.