ORIGINAL: proptop
Would(n't ) the tail volume (especially the horiz. ) have a large impact on the ability to move the C.G. aft to or perhaps behind the N.P.?
The larger the area of the stab. the greater the ability to remain stable in pitch as the C.G. moves aft, to or behind the N.P.?
The larger tail volume will move the neutral point (N.P.) back further towards the tail. Moving the C.G. behind the N.P. will still be unstable, even with the bigger tail volume.