It is not possible to set up a policy to create databases on multiple servers when you initially create the database.  Yo can do this during the initial registration of a user, because the registration process works through the Administration Process.  If you create a new database, you must then immediately (and manually) create a new replica on the desired target server to ensure that it is on both servers.

Create a schedule agent that would  loop thru the directories on the server then try and open the db on the cluster pair and if not there would create a replica copy.  There is nothing that is built into domino