Along with the problem of the control forces of the movable stab being fought by the fixed stab there's the problem of the sizes of the stabs. In our model sizes there's already a bit of a problem with the tails being so much smaller than the wing. To compensate for this it's commonly realized that the stabilizer aspect ratio has to be considerably less than the wing aspect ratio when gliders are being designed. Now you're suggesting making the tail surfaces even smaller and splitting them up. The resulting Reynolds numbers for these surfaces will be super low resulting in even worse "scale" effects than we have with one surface.

I like different too but in this case I just think it's a bad idea to use multiple tail surfaces in this manner.

Full moving tails are more efficient? Yes and no. It depends on how much travel you want. For gliders where the tail is more of a trimming surface full flying is the way to go as it eliminates the hinge line (but be sure to seal the stab to fin joint with something like felt or the leakage drag will eliminate any advantages). But for a 3D aerobatic model the fixed stab with movable elevator forms a variable camber airfoil that is less prone to stalling until higher deflection angles are involved and, if done right, are capable of higher lift coeficients thanks to that camber.