The smart computer groups are normally for scoping a policy or configuration profile against, not really for data gathering. It sounds more like you want to create an inventory list of all computers and details about them, to do this you probably want an advanced search. Have a look at - http://docs.jamf.com/9.9/casper-suite/administrator-guide/Advanced_Computer_Searches.html
This really brings me to the question of what are you trying to achieve?
