Zygopetalum taxonomy confusion: maculatum vs. intermedium vs. mackaii vs. mackayi

[BrassavolaStars]

Hello all,
I have recently acquired some zygopetalum species.
One of which is a maculatum and the other is an intermedium. Additionally, I’ve been eyeing one listed as mackayi.

Before I bought anymore zygo species though, I have been reading up on zygo taxonomy and it seems that some guides say these species are all the same and that mackayi and intermedium are just synonyms of maculatum. Is this true?

To further complicate things, other sources say maculatum is a distinct species but that mackayi and intermedium are synonymous. Still, a few more guides say mackayi is different from intermedium but the same as maculatum.

I am so confused. Are these all just synonymous? Are some of them synonymous but one of them isn’t? Even more confusing, some sources list both a mackaii and a mackayi.