The only complaint.

[ManuelBravo]

eh?
That's like saying if you flip the four corners Aerith will be brought back to life.
Proof, or it's unsubstantiated nonsense that will only confuse people.

We all have our methods then, to each their own. Main point is you have a better chance to get cards you don't have by challenging NPC's then wasting MGP on packs on repetition based on theme and not likely to get the ones your missing.