Hey Ash,
The thing about longer page lengths is not so much that they have more words per se, as much as it is that a 1000 word page may contain a _broader vocabulary _as compared to a shorter page. However, I can give you countless examples where a 300 word page outranks a 2000 word page simply by virtue of the quality of the writing. So, even though everyone seems to be all hung up on "more words are better" you're better off thinking about how well do you understand your audience's questions and how thoroughly have you answered them.
Ultimately, however, ranking is not just about the words on the page, but about your audience's experience with your content--are they clicking through, are they spending time, are they sharing. In order to push you up in the rankings, Google wants to see that your content is important to your audience and its vocabulary is only part of that equation. I might recommend Rand's content manifesto for some inspiration on how to move forward with your site's content. I think what you've described so far is a good start but there is an entire universe of directions you can take it and now may be a good time to start looking at the bigger picture.