Exactly, the Neutral point is set by the tail volume. The Np and resulting CG range is set by the planform of the design. And as pointed out nothing is cast in concrete. Up to a point the final CG position on any model is determined by your tolerance to dodgy pitching stability or lack of stability. A model with a CG at or VERY slightly behind the Np will be flyable but it'll need constant attention. But move it too far back and it'll exceed the ability of the pilot and radio to input corrective actions quickly enough.

There's a lot of misunderstandings about all this. One area I see this in a lot is the conversion of old timer FF models to RC. In many cases the models were made to be stable with a CG at the 40 to 60% range yet many folks try to balance it at the typical 28 to 30% point that they are used to using on "standard" designs with smaller tail areas and lenghts. In some extreme cases of competition FF models from the 50's the CG was at or even slightly behind the wing's trailing edge. But the models were still stable at that point.

There was a chart around here that was made up by one of our more technically savvy guys that showed the progression of the NP location as the tail gets larger and larger. It started as a normal looking top view and progressed to a full on canard at the other end with various stops along the line to show extreme large stabs and a tandem wing. You see, there really isn't any different planforms. It's just a case of the stabilizer getting larger and larger. You can actually use the Np determination for all these various planforms and it'll work fine. In the case of the canard your "wing" is just a lot smaller than the "stabilizer".