Guidance Needed: Setting SLAs for Advocacy Requests Management

Hello! does anyone have any guidance or scaffolding around SLAs for fulfilling advocacy requests. We're struggling right now with various teams throwing a ton of requests at us with tight timelines that they feel are ALL high priority. It's less of an issue from sales re reference calls etc and more so from marketing/PR/comms who seem to be juggling a ton of competing priorities and it's all rolling down hill, but would be helpful if anyone has set SLAs for various activity/advocate requests! We're trying to set some documented boundaries and expectations about how much lead time they need to be giving us for some of these requests (speakers for webinars/panels, quotes, permission for media mentions from higher profile customers, etc.)