Sometimes it is important for you to be able to make a lot of changes to your existing website so it's best if you can do them yourself. However, unless you need to update your site on a consistent basis, adding a Content Management System adds cost to your project and is probably not necessary to include in your project.
The issue to be careful of when it comes to content is that the major search engines are influenced by the way your content is displayed. As professional web designers, we are familiar with the best ways to present content that will attract Google and the other major search engines.