[ANOTHER FLAME WAR] Are dragons overpowered or not?

Okay, show me the "rule" that states that, for example, a sphinx must have the body of a cat and not a dog. Or that a minotaur must have a bull's head and not a rat's head. These are mythological creatures, not real ones. The neighbor from the stairwell, during a break between swigs of cheap port wine, might say that a minotaur should have a rat's head. Since minotaurs don't exist, why couldn't he be right? So, the neighbor is right? Are these stereotypes? I'm having a discussion, not making personal attacks. But these childishly categorical, albeit sometimes humorous, loud statements that "I'm right, and everyone else should shut up," or that something always happens one way and not another, directed at me, are very irritating. Or when, unable to refute someone else's opinion, they start accusing them of being stubborn. Do you understand?