That's a good question. The problem I have found is that not every cable works well in all systems. Matched or not.
I have two MAC HC Soundpipes on my CDP and amp. I didn't mean to match them, I just tried the MAC and liked what it did on my CDP so I bought one for my amp.
I have found that if I buy one PC that does well with my source component, it will do well with my amp also.
Mix matching works well also if your tuning with the PC's.
Find a PC that works well on your source and chances are it will work well throughout the rest of your system.
Again, it's not to say that you have to use matching PC's, it's the synergy of one that works on the front end should work with the rest.
Hope this helps.