If you enable the “Front end registered users should be saved as agents?” option from Theme option-Membership and Payment Settings, the user will be the same with the agent and you will have the name of the agent. This is in case that users add properties.
If you add properties and then assign them to agents, you will still have the name of the user-admin there.
We can change that only with custom work. If interested, please open a ticket here: http://support.wpestate.org/