I run everything off the same cluster in my home lab just fine. I wouldn't recommend it for a "production" environment though.
In order for VCD to load its agent onto each host it has to be evacuated and put into maintenance mode so you need to have enough free compute room for this process to complete.
You will need at least 2 VLAN's setup though. They can be existing portgroups. One will be used for the Network Pool and the other for the External Network.
-Eric
