In my direct experiences, moving to a single brand matched array / loom of cables MAY ( emphasis added) provide an audio performance improvement and synergy.
BUT … I only found it mattered on limited circumstances contributing factors:
(1) only in high-end pricepoint strata brands ( for me, CARDAS & NORDOST) …think CARDAS CLEAR …
(2) It is ENTIRELY system dependent and there is no one-size-fits-all general rule. I have four 2-channel systems ranging from $1500 to $50,000. . Only in the my “A” system did It matter. In lesser build and lesser pricepoint systems …. Nope. … nada perceived differences.
The added synergy and ethereal audio performance was definitely there , but it was on the subtle or “softer’ side instead of any “AHa!” Or “ Jesus” moment. For example , adding a final piece with a matched speaker cable in a sequential cables CARDAS CLEAR arrray upgrade from NORDOST FREYs, finally tamed an ethereal “brightness” or “digital edge” that still existed until the NORDOST speaker cables were removed as the final link.
Choose wisely