So in this case, both can corroborate their findings because both demonstrate success in learning to read?

Since you said both look at controls to assess that they're better than random ?

But from the article, it seems to imply there hasn't been controls applied to the three cues system. Therefore it would have always remained just some children become good readers with this methods, so it probably works.

And what I'm not able to gather is, how much better are the controls applied by the cognitive one?