I still consider myself a newbie, but thought I would toss this out anyway.
I'm not sure about AIX, but my unix system the netstat vs ps information differs in the following ways:
netstat -a As you said, this shows active connections. If the connecting machine is in the hosts file, it shows up as the host name. If the connecting machine is not in the hosts file, it shows up as an ip address. netstat doesn't show what those connected machines are doing.
ps -ef This will show processes kicked off by the connected machines. In my limited experience a particular service can have multiple different processes.
I think what you are experiencing is what you should expect. Hopefully someone will correct me if I'm off base.