Having the Agents and Requests separated makes it harder to search for people in the system. There should be an All Users search with a subcategory of Agent and Requester, rather than having them separated.
All Users should also be requesters and then have the added feature of being an agent. You should be creating people as requesters first then marking them as an agent. Rather than separating them into two different categories. Agents can also be the ones who log tickets and makes it difficult to configure anything based on these being separated.
