The usefulness of the concept of tankies is in part that it's so poorly defined that the category can shrink and expand at runtime to prove whatever point you want. Global South brown people aren't tankies (as long as we're actively entertaining that brown people exist and have their own subjectivity) because if they are, suddenly 95% of brown people who are leftists disagree with me and that'd make me look racist.

Chomsky isn't a tankie because he's said a bunch of things I agree with. But also he is a tankie because he defended the Khmer Rouge and was friends with Epstein. (surprised that the OOP didn't take advantage of some of Chomsky's uncharacteristic takes to make that point)

Foucault wasn't a tankie because he had a nuanced take on Israel (read: he was a zionist) and was very critical of AES. But also if his support of pedophilia is brought up he can become a tankie because he supported the Islamic Revolution in Iran.

These are 2 examples who are real people who have written about their political opinions extensively yet it's definitely possible for someone to find reasons to put them on either side of the "tankie" divide. If you want to do it with a more nebulous entity like a political community, hypothetical people (like the latter part of the OOP), or a whole country, you have infinite wiggle room. Anything can be used as a data point because the word is meaningless.