Some meetings matter more than others, and some are  important enough  to invest significant amounts of senior leadership time.  It makes sense to get  external help for such sessions. Typical reasons for investing in facilitation include the importance of the topic and the need for people to be  able to work creatively and deeply  on something hard, or the degree of difficulty in building  alignment.

If this meeting really matters then a moderated session can help ensure success.  You need  to be willing to invest in bringing people  together in an appropriate environment (one without screens or tables), where you  share responsibility  for the design and moderation of  the conversation.