While we agree in principle, we really don't have enough information about the constituents of mushrooms.
Yes, we know there is psilicin and psilocybin in them but we really don't know what modifying chemicals may be in the fruit. We see a third element, that seems to introduce a frantic, speedy effect, baeocystine. Others are or may be
norpsilocin,
norbaeocystin, and
aeruginascin.
Now I have tried some 5 or 6 varieties but could never tell you the difference. I, as you, believed that a cube is a cube is a cube.
Others swear their are such differences.
The variable nature of the experience makes it difficult to really tell if the mushroom is different or if it is just a different head.
I know of an odd sort of strain where I heard at least four separate people, people who did not know each other describe their experiences as being predominated by "pink". They felt pink or they saw pink tinges or they were somehow so influenced by the concept of pink that they brought that specific color up to me.
Now I had to try this and I did notice pink in the experience but who is to say I was not influenced.
My point is, marijuana has a half dozen affective compounds in it that make one plant different than another, peyote has a dozen. The coca plant has more than a dozen. The opium poppy has more than a dozen. We cannot yet say what a fungal chemical factory that has a penchant for producing serotonin like analogs might be creating and what various combinations of those substances might be doing to our consciousness.