Build each page for each keyword phrase for optimal results. Period.

Just look at the searcher’s intent. They don’t go to Google or Bing and type in two or three phrases, do they? Don’t build a page, then, with two or three phrases. Build one page per keyword phrase and then optimize.

See Rand’s explanation for more detail: http://www.seomoz.org/blog/tactical-seo-how-many-termsphrases-should-i-target-on-a-single-page