Kphinney
I'm sure a good portion of your thoughts are quite valid, especially those regarding the use of 'same same' from the cable makers viewpoint.
I've had two shots with same same cabling throughout, first was Voodoo and second was Shunyata. Not all the same models though in each instance, as was the suggestion of the maker.
With regard to optimization of a system.... well we're back into the land of subjectivity once again.
With power cords only, I was running 4 Taipan Helix A's throughout with one Python Helix A for a little while, and the sound was quite cohesive and the tones were most vibrant and colorful. I found the top end a bit more prominent than I would prefer however. I could only swap the Python source cord and preamp Taipan cord as I run mono blocks. Keeping the Python on the source proved best.
since then the gear has been elevated IMHO. I still have a penchant for the Taipan Helix A, and the older Python ()red) VX. I've found other pcs which have the attributes my system needs and I prefer since then. That said, I'm considering adding back in a Python Helix A once more for one of it's main characteristics.... and an Elrod Sig II for likewise reasons.
Once a base line of performance is noted objectively as possible, integrate one cable at a time and after some run in, swap it about. You'll quickly see where that particular wire is best suited. Makers of the wire itself can point you in a closer direction, yet you will always be judge and jury.
As I do not have a one brand system, or even if I did, I don't run a one brand wire loom throughout it. I do enjoy the results of that path.
In my own exp... with a fair amount of trial and effort, the cohesive, congruent, and imersive quality one seeks from their stereo can well be attained by using several different brands & models of cabling about it.
I sincerely feel each approach custom, or likewise, as justified, yielding still great performance. This wire business is tossed about so much by the proponents for either side of the affair, I'm pretty sure from my own limited exp that all roads lead to acceptable ends.
Barring costs, the quicker more simplistic and shorter route is that of 'same same brand' yet maybe not all same models. EX my Elrod Sig III works best when a lot of juice is flowing through it so it's not a pre or source cord. it's best suited for conds, and amps.
So you choose. Do the Zu thing all over. Later on go pick a more specific application cord at a reportedly higher level of performance, and insert it intuitively, ans see for yourself!
I feel every component made has it's own strengths and weaknesses. Wires too. Consequently, my argument or philosophy follows then, that each appliance has specific needs and as such, may well require specific cabling, and maybe a one brand approach doesn't meet every one of those needs. Let's not forget personal preffs and budgetary restraints too!
The question then remains: So you have picked out the most optimum cord for each of your pieces?
Nope. Probably not. there's way too many cable makers and they keep changing them too. I'll settlle for 'Satisfactory' or as best as I'm able, over 'optimum - perfect'. I think that's the best anyone can do.
Perfection in an imperfect world is a frustrating wild goose chase. This hobby is always going to be a "best effort" affair... and never perfect, save for it's owners subjective account.
Have fun, I'm sure things will work out for you.