You can include anyone!
The people who make an impact on you and your organization include coworkers, partners, contractors, freelancers, customers, clients, etc. Include them all. The more the merrier. Naming a 3rd party in a story is a great way to engage them and build loyalty.
Note: Your organization may have specific policies related to who you can include in a story. If you are unsure please contact your GoodSeeker administrator.