The WS winners have proven you can win it all with various combinations of being really good in some areas and okay or even bad in some other areas. Certainly, being good on batting and pitching is more valuable than defense and base running, but all factor into how much you win or lose. The Royals won with a crappy rotation, but a great pen, defense, base-running and decent hitting. It can happen.
We all know many teams have won with okay to bad and even horrific defense. It can be done. Nobody disputes that fact. When the Sox win, it's almost always because our batting was great, we had a decent closer and or pen, and a healthy and productive rotation, usually with 2 TOTR type SP'ers.
Our home park will always improve our league rankings on batting, so that has to be factored in. It also hurts our pitching rankings.
Ring Rankings (Batting wRC+, Pitching- fWAR, Defense, Running)
Year B-P-D-R
2004: 1-4-24-30
2007: 2-6-14-19 (If you notice, we fell in B & P, but D & R picked up the slack.)
2013: T1-14-11-5 (one could argue the D & R covered for the average P.)
2018: 4-6-15-20 (A pretty well rounded team.)
Max, one could bring up several examples where the Sox were better in batting and pitching than the 2013 team, yet did not even make the playoffs. It would prove nothing, but it does raise questions about your methodology on determining why the Sox win rings and how little defense matters.
BTW, that 2015 KCR team:
10-14-2-17 (20th in SP fWAR)
Middle of the road batting
Bottom 11 rotation
Middle running
2nd in defense.