When is a Sample or Remix an Artist?

How do you (and anyone else reading) think the following releases should be credited?

All the tracks on these three releases are mashups. A mashup is a remix or megamix that uses major parts of two or more songs. Many mashups are unauthorised. Of the three listed here, the most deceptive is “Dukku Dukku”. The actual recording artist is Soulforce, but that name does not appear on the record. Instead, it only credits the sampled artists. That caused some confusion when the record was released in 2011.