Actually there is not that much difference and what difference might be related to the fact that AL doesn't have their pitchers bat like real baseball players

Cardinals score 3.99 runs per game (recently dropped below 4)
Royals score 4.52 runs per game

Cards have a run differential of 114
Royals have a run differential of 80

Cardinals ERA is 2.90 (recently went up)
Royals ERA is 3.75 (don't know what it was before you picked up Cueto)

Direct comparison Cardinals have won 4 of the 6 games with the Royals this year-- most of the games have been close

Only real difference is the Cardinals are in a league that plays baseball as it was meant to be played ......

and they are in a more competitive divisional race (see the NL Central 3rd place team's record)

So before we get the old if your aunt had balls-she would be your uncle (I'm wondering how you know about anyone's relatives 'plumbing')..it doesn't take away from the Royals on the verge of winning their division but it does point out how the Cardinals have had to play to have the best record in baseball.

Now answer LS questions about the old cuban guy running the bases

just saying