I've had good success in both high-skill teams (in one case, almost half the team's engineers ended up at Google at some point or other) and... teams that were still in the process of skilling up. I've found people generally want to do good things and have some room to grow even if they're not yet at your desired level; and when you have demotivated people around, the causes tend to be systemic. Which, thankfully, implies possibly fixable.