I do not think this is possible.
Running two agents on the same machine is not possible, and it really would not matter, as the agents report to the Tomcat server(s), which in turn communicate with the database.
You *may* be able to do transaction log shipping between 2 databases, but that is a question for a DBA.
What is the reason between not having one centralized database? With the proper SCSP IPS policy on the database server, you can lock it down so nobody can edit the database, if that is the worry point.
You may also may be able to use a SQL cluster, and have one team use one node and the other team use the other -- but again, I am not a DBA . . .
If you could explain the rationale for this setup, we may be able to offset the perceived risks by other means.