Search engines do not care how long your content is. If they did, and you write 1,500 words, big freaking deal. The next guy is going to write 1,600 words. The guy after that will go for 1,800. Then 2,000. You get the idea?
If it was really a ranking factor, everyone would be writing a minimum of 10,000 words on every page. Fortunately, as can clearly be seen if you actually look through the SERPs and study pages that are ranking, content length does not play a role in ranking for a specific keyword.
Where it can be beneficial is with longer content you can hit on more related keywords and LSI terms helping the page to rank for a bunch of different, closely related keywords. But if you are just talking about 1 specific phrase that you are targeting, the length of your content does not matter.
I have never encountered one single professional SEO that paid attention to word counts.
The only people who tell you that word counts matter are people that do not know any better and are just rehashing garbage they heard from wannabe SEO gurus.
And that video from Matt Cutts does not prove otherwise. He is talking about doorway pages, shitty affiliate sites, and sites that are just syndicating content with no value. Nowhere in there does he say that the longer your content is, the better it is for rankings.