Hi,
Thank you for your question. The scope of AEM Commerce Integration Framework (CIF) is a typical B2C store front customer journey and does not support impersonation by 3rd parties. However, you could extend CIF and add this functionality as a custom extension.
Your first step is to figure out if hybris' OCC v2 REST API layer (which we use for the integration) supports impersonation. If not, you would need to extend their OCC API layer and expose impersonation first. On the AEM side I would integrate the impersonation functionality in the Context Hub. Your sales person could then pick the person he wants to impersonate via Context Hub.
Unfortunately, I don't have any real-world example or experience I can share with you.
hth.