2 of 4 capitalization

Can the web content creation and UX process start simultaneously? How?

I work for a digital agency on a commercial website for a client, we are creating a website from scratch. A third party agency is assigned for content creation. As a UX specialist I am assigned to create the sitemap and start the design process for the website (wireframes / visual design). I have provided an initial sitemap based on competitors' content, and due to a tight deadline, we are forced to start designing without content provided. My questions here:

  1. Can we start working on wireframes and visuals without content? Is there a best practice for that to minimize the hassle of the process?

  2. If both the digital agency and content agency are working at the same time, what kind of deliverables or alignment documents should be provided to each assuming the content agency doesn't have a content strategist?