I am shocked how misinformed and technically misleaded a pro team like the guardian is. Saving your stories in HTML in a CMS? This is like using Joomla for hobbiest sites or something like that, it will kill your archive and it will be a pain reusing content.
A good Content Management Strategy is: use libreoffice for wirting, create a plugin that publish to archive and put articles in the pipeline for redaction, save content to docbook and be prepared for any kind of reuse of that content.