Parallel drop/create on postgres using DBA fails with: ERROR: tuple concurrently updated

We have N number of separate processes that can kick at the same time which all talk to the same postgres database. These "processes" are jdbc code which drop a user/schema and then recreate user/schema. We do this by connecting as a DBA user which is used across all processes. Each user/schema is unique so it's not as if all processes are attempting to drop the same. With that said 1 process will always succeed while the rest fail with:

ERROR: tuple concurrently updated

We are dropping with the following code:

            String postgresRevokeUser       = "REVOKE ALL ON DATABASE " + postgresDB + " FROM " + this.getUsername();
        String postgresDropSchema       = "DROP SCHEMA IF EXISTS " + this.getSchema() + " CASCADE";
        String postgresDropUser         = "DROP USER IF EXISTS " + this.getUsername();

        connection = getDbaConnection();
        connection.setAutoCommit(false);

        statement = connection.createStatement();

        statement.addBatch(postgresRevokeUser);
        statement.addBatch(postgresDropSchema);
        statement.addBatch(postgresDropUser);
        statement.executeBatch();

        connection.commit();

I can easily imagine what the issue is just don't know how to get around it (without putting in some synchronization between processes but that will be a fair amount of work). Any help would be great.