Hi (soon2B) S-rider
Yes, it's a long and complex discussion, but overall width and tail width together with volume all influence a planing board's "performance " sizing, c/w only considering absolute displacement volume.
For most situations, you should not select a board ONLY on width or ONLY on volume, rather on a more combined understanding of how all these factors will influence your (personal) situation when using the new board.
Please let us know if you would like more information on this,
or how it would relate to choosing the optimum board for you..
Cheers ~ Ian