The post is not about the word. The word is only used as an observed object. Could be “fhbvjfba.”
But following the topic you touched: there is nothing wrong with word “anisosquaric.” Natural languages have no rules. There are only observable patterns. Often they don’t apply to all or even majority of native speakers. There is no pattern for English word formation requiring morphemes to come from a single language, or demanding foreign language’s grammar to be followed.
There are no foreign words involved too. I believe you assumed “aniso-” is Greek, but it is not. All three — “square”, “aniso-”, and “-ic” — are English.
The reason you don’t see “polysoundic”, “multisonic” or “polysonic” is not because there are some “rules.” It’s because they never appeared or didn’t gain popularity. Contrary to what you think, “multisonic” and “polysonic” are in use.
Returning to the original topic: 3 hours later LinkedIn also started offering anisosquaric jobs in India. 11 hours later you can buy “an
siosquaric” a waffle makers.
