It might be technically possible, but there is a lot of logical separation that needs to happen.
1. When installing vCloud, you cannot duplicate the installation 'System Name' or Installation ID across all instances. the Installation ID is cannot duplicate vCenter's Installation ID as well
2. It would be best to have a unique Distributed Switch per Cluster (per provider to a given vCloud Installation)
3. You'll only need 1 vShield Manager, since it's paired to the vCenter installation ... not the vCloud Installation.
4. Don't overlap other items (IP ranges for public networks, vLANs in use)
5. if there is VXLAN in use, ensure to use different scopes.
This isn't even an exhaustive list.