Well we, as humans, know how our world works - so even fictional ones have to follow the same rules. Even alien planets follow Earth's 'rules' or else it's a hurdle for effective storytelling. Like air always breathable, lighting great for the human eye, gravity for action sequences and more.....
Whether it's wrong or right, we only know two animal scales. Dinosaur and jungle animal.
So overall, it just has to make sense and be familiar enough to feel real and if not 'real' real enough to be plausible.
To your question, execution is everything.
@Kiznara has (probably) mastered those aspects of storytelling so they can get away with it.
If you were cleaver enough, you can make a MAIN Character that has no name.
Yep, the movie Drive with Ryan Gosling - he is never named or given a name or is referred to in a direct sense.
Is that what a writer *should do?
Or give the protagonist a name that's hard to remember...hard to spell....hard to pronounce....
that doesn't match their gender or, or....
BUT! if yu do it right then all bets are off.
So yeah, execution is the key thing.
Common sense says eliminate the amount of things you need to get just right by sticking to convention.
And then, here come the tropes.