Hi,
Without CM you can not generate reports based on RDR collection process. For example if you dont have Collection Manager you can not generate reports that are predefined on the SCA Reporter or insight. Only you can do is you can poll SNMP counters/values by a s/w and you can graph them, but it is not suitable and not covers the all data that SCE collects and reports. And for the SM side if you want to communicate with a policy/external server you really need an SM, also you can use its internal Quota manager to count quota.