Many writers can 'sprinkle' keywords throughout articles/blogs/websites. SEO content is not that easy. The guidelines change what seems like weekly, and the placement OF the keywords is as important as the keywords used. I was one of the first SEO writers online three decades ago and I train and educate myself monthly. I write for some of the top SEO companies in the world. Do not shortchange yourself with a 'possible SEO writer.'
Check ratings and if you do not see enough large SEO companies among the rankings, then you do not have an SEO writer working for you as most of our business comes from referrals. Just being real here!
And remember also, all the traffic in the world will amount to nothing if you do not experience clicks and conversions. I can make BOTH happen, rankings and conversions. Try the best before you try the rest! Content that is MEMORABLE. That keeps others coming back each and every week or month.