I've won 96 games and a WS with just 1 true power hitter. He ended the season with 43 HR, and one other guy had 20. (106 total HR)
I've won 108 games without a true HR threat. We only hit 71 HR, but hit 124 triples. Our top 4 guys had 16, 13, 11, and 10 HR, no one else had more than 5.
Like rbow said, a strong hitting team in a park that fits their strengths can do very well.