okay this is really my lack of ability to articulate or plain stupidity  i think what i wanted to reflect was one can do a create firewall without supplying a router id or port id list  and in that case the firewall will be in a pending create state  the logical resource is created but has no binding to any router or ports  once we update the resource with a router or router list of ports these columns will be populated  so in that sense it is not required but that only implies logical resource creation  the pending create state is in line with the current implementation 