Yes, interesting. I don't know how these numbers were obtained, and what was happening on each machine when the speed tests were run, but I find it interesting that what appears to be the same machine would have such disparate speed test values: for instance, two of the 4TB numbers listed are Write 6626MB/s as well as Write 7398MB/s (significantly different values). I think this is the reason why I always run these SSD tests on new machines without any data or extra programs loaded and freshly booted. Repeated runs (after the new machines had finished their indexing/optimization) then yielded much closer numbers in my hands...and I got nearly identical R/W numbers on both 2TB and 8TB Apple SSDs.
Probably variations in second source components for different storage controllers and NAND.