Cleveland just won a championship by tightening up their team defense.
Each championship team I've seen has one thing in common...they score a comfortable amount of points more than they give up.
The "Bad Boys" of Detroit late 80's team had a team full of rough tough defenders, and a few guys that could really score, they won games 92 to 85.
The "Showtime" Lakers scored a ton of points at a fast pace... their defense was "good enough" They won games 121-112.
The Celtics of 1986 scored points by clever passing, 3 point shooting, and "good enough D" They scored at a great pace, and gave up less than they scored...almost every night.
Each championship team I've seen has combination, and a balance of both. You deal with the cards you were dealt. If you were dealt tough defenders, then you go with it, or trade everybody away... and pray.
I'll gladly take a team that gives up 85 points, and scores 92... if it means a ring.