All I can say is that vendor I am getting kratom from (shipping from Europe) for more than 5 years always had this strains (names): Thai (always only red and specifically said that it is banned in Thailand so that these trees are grown/farmed in another location), Malay (always only green), Borneo (specifically said that strained named Bali is actually Borneo as there is no kratom grown in Bali, and they had red and white), Sumatra (red and white), and Sumatra from Riau region (only one that they had all 3 colours).
When they started adding new strains or better to say new names - they specifically said that it is different way of drying or that it is based on some extract of kratom they already offer. They have no horn leaf or any funny names (except few blends that they openly say are not some specific strain but that they made some extract from Malay or Borneo kratom and that they are mixing it with other regular powder kratom). They were and still are pretty open about it.
With all this said, I can not find how Green Malay could be same strain as Red Thai (from this vendor). They are every time distinctly different. I have made blind dosing to my wife and SHE COULD EASILY TELL! There are differences in potency from batch to batch, which is expected from a plant, but I can tell very profound difference eve between Red Thai and Red Borneo. I have decided to limit my intake to Red Thai and Green Malay (as they seemed best value for money and they do feel different than let's say Sumatra White) but occasionally do buy some blend that they mix up.
If the thing about strains of kratom is true and that there is no difference between trees grown in Thailand vs Malaysia vs Borneo, I would be very surprised as I am not that prone do be deluded.
I do agree that some exotic names are not reflection of a true difference, but also think that there is a basic difference based on where (what island) kratom leaves are picked from and what technique of drying (this is secondary) is used. But there are only 4 different kratoms that I am truly aware about - Thai, Malay, Borneo and Sumatra. If they are all one and the same in their effects than I will question are morphine and oxycodon actually the same molecule just advertised differently.