No each agent can only be assigned to 1 team 1 Resource Group. You could just do agent based routing. Assign skills to each agent along with a compentency rating. The only problem with that is the people with the higher skill level will get more calls.
On a side not if you are using CCM 5.1 along with CCX 5 there is a bug in it that will send multiple calls to one agent the agents screen will flash between reserved and ready the call doesnt drop but it shows up in the reports as an abandoned call. You have to upgrade to UCCX 7.0 SR03 for the fix.