[Celjabba]

I have mixed feelings about this.

On one hand,

as a player, it is frustrating when a NPC "break the rules" that you have to follow.
To take a non-rpg exemple, I remember having a fit of rage over the videogame "sid meier pirates" where in high difficulties, the smallest npc ships would carry 4 times more guns and crews than the player could on the same ship. (and they were faster too ! stupid cheating computer)

On the other hand,

TTRPG are not videogames : they have a GM, and the GM word is the rule, so ... there cannot be any npc "breaking the rules" by definition.
Larsdangly above seem to say that he would be ok with a knight with demonic ancestry having 44 (for exemple) in stats but not a mundane knight.
I certainly understand the feeling but since the GM decide what the NPC is, it is in a way a very arbitrary ok/not ok.
In a game where you play a character, and the system is only there to support the game, I feel an NPC breaking the rules is a non-problem.

On the third hand,

For Arena games, or games where the GM is only the arbiter of rules in a strictly defined setting, having mundane npc following the rules governing mundane pc is important.
Not for fairness, but because a player in such a game need to be able to rely on his knowledge of game mechanics.