We had identified a very large group of interested (and relevant) parties for the homepage workshop, 17 people to be exact.
We were initially concerned that it would be particularly hard getting people to buy in to the workshop and actually put forth ideas, because they were all hyper-fixated on their sections of the site.
Start by discussing the content and technical requirements.
In order to make sure there were no missing pieces of content/functionality accounted for on the homepage, we set up a whiteboard to collect any content and functionality requirements for the page as guidance for the group during the rest of the workshop.
Split into diverse teams for prototyping.
For the actual prototyping exercise, we divided the group into 3 sections, with each group including one person from each business unit to ensure the thoughts identifed are diverse within each group.