SME offers the ability to license per server or per NetApp controller. In your case you've licensed based on the controller, which means all SME instances which utilize LUNs on that controller use the controller license.
When you perform an install of SME it will prompt you for one or the other.
Details on licensing options are available in the SnapManager for Exchange Installation and Administration Guide (IAG), Chapter 2:
http://now.netapp.com/NOW/knowledge/docs/SnapManager/relsme50/html/software/admin/preinst4.htm
From a testing standpoint (such as use of the simulator), it's much easier to use a controller-side license rather than per individual server.
Thanks,
--Matt