Scamie, the other plant in that pic appears to be a very unhappy kratom tree.
Soulcatcher, the thing about using the internet forums is that everyone (myself included) thinks that they're an expert and always 100% right.
In the other thread you mention that they're only 5cm tall. I was looking at them as if they were 4 times that size. If they're that small then I would like to take back my previous reply where I stated that the spines are too long. They very well could be pachanoi.
Also, I've only been growing these cacti for 5-6 years but I have never once heard of a spineless pachanoi.