Helping to answer the difference between a Run Data Load Rule command and Run Plan Type Map are crucial. They both may deploy a common technology (Data Management) to achieve this goal; they go about it in different ways.
The EPBCS Run Plan Type Map is mostly used to copy data between databases within the same application. Example provided by Oracle: Copies data from a block storage database to an aggregate storage database or from a block storage to another block storage. Most all of the settings, configurations are performed automatically because you are within common metadata/applications. The system then behind-the-scenes builds and executes a Data Management processes it will execute as necessary.
There are technical limitations to Plan Type Maps that are covered in the Oracle documentation.
The run Data Load Rule is a lot more flexible in that it opens up and exposes the full extent of the Data Management application. This requires the end user, or Administrator, to have fully configured source/target systems, defined mapping, system settings, system properties, etc.