A brief update on progress made:

I was able to persist the correct table name by modifying org.hibernate.ogm.persister.OgmEntityPersister's constructor:

tableName = persistentClass.getTable().getQualifiedName(
factory.getDialect(),
factory.getSettings().getDefaultCatalogName(),
factory.getSettings().getDefaultSchemaName()
);

replaced with:

tableName = persistentClass.getDiscriminatorValue();

I understand that this is not a solution, but was an attempt to isolate the problem. Another approach tested was the addition of a (invalid by OGM docs) modification of the Base class:

@Entity
@Inheritance(strategy=InheritanceType.TABLE_PER_CLASS)
public class Hero {

This change also produces the correct persisted table without modifying the core OGM code. This kinda makes sense since orm is being asked to derive the table name and if I recall correctly JPA defaults to SINGLE_TABLE in the absence of @Inheritance.

While these approaches seem to solve the table name issue on persistence, re-hydration is still problematic. I'm going to move on to that issue.