There have been different types of RPG’s among videogames for a long time. Both Witchers are third-person, single character action RPG’s. Dragon Age: Origins on the other hand, like its supposed Baldur’s Gate ancestors, was a party-based tactical RPG.
The first Witcher did share some characteristics (more than usual for an action RPG) with party-based tactical RPG’s, which is not that suprising since it used an old BioWare engine. That does not make The Witcher II less of an RPG than the first one, it’s just more purely an action RPG and less of a hybrid.
The Witcher series is just evolving towards a direction that is only natural for an action RPG, while DA is evolving away from its original party-based tactical RPG characteristics to an action RPG with some vestigial party-based tactical elements. Further evolution may turn the other party members finally into non-controllable, fully AI controlled NPC’s, who can be only given very rudimentary orders.
I think one can argue that Elder Scrolls is also moving into that direction with its companions, and there’s no reason why future CDProjekt RPG’s can’t do the same.