I don't agree that Machida lacks power.
He is very powerful, but he doesn't follow through.
Machida is like a laser-guided bomb, whereas other fighters are like carpet bombing.
He doesn't strike unless he's pretty sure he will hit.
It's a direct result of his point-sparring/shotokan karate training.
It stands in contrast to more aggressive styles like Kyokushin/knockdown karate and Muay-Thai, but it's worked so far.
He's beat Franklin, Bonnar, and an inflated BJ Penn.