Hi Prema,
I want to go with the suggestion of Ashish. SWCV how we define is more towards Business Processes, not like number of Systems (Sender / Receiver) other than Technical ones like Basis/APPL/Standard Contents (SNC, Auto ID etc.). Namespaces are specific towards Interface functionality, means how an Interface is implemented to accomplish a sub part of the Business Process.
I am not sure whether these 8 interfaces are performing any common process or not. Suppose you are implementing 'Procurement' for SAP, then may be you have a single SWCV. Under that Namespaces for example:
urn:XXXX.com:XXX:Procurement:CostCenter
urn:XXXX.com:XXX:Procurement:GeneralLedger
urn:XXXX.com:XXX:Procurement:Supplier.............
Regards,
Nabendu.