This is great information; yes! you are making progress.
I have a recommendation for you. Since you know that oracle and grid are local users and will always be, add them to the /etc/centrifydc/user.ignorefile. This will effectively exclude them from us thinking they are our responsibility.
After you make any changes to the user.ignore (or group.ignore) file, it will automatically will update the uid.ignore (or gid.ignore). You should issue an adreload command.
The source of truth here comes from an SME for the application. If the app is making non-optimized calls like "get me all users, get me all groups, bypass the cache" other than optimizing the app there's little that can be done. This is true since the old days of NIS.
R.P