The RPM's that you are missing on the Enforce box are required to run ORACLE on ANY linux server. So I think someone might have already installed those RPM's on that server, otherwise Oracle will not run.
So if you do install Enforce on the same server as the Oracle DB, then you DO NOT need to install an oracle client. Follow the instructions that are in the Installation guide for Linux. It will tell you all that you need.
Make sure the listener has been configured on the Oracle box as per the Oracle installation guide.
Hope this makes sense.
If this solves your questions please marked as solved.
Ronak