Pretty subjective I think... Theres too much going on to call it out all on one single factor. That said longer scale will make it easier and more viable for lower tunings. Its a fact. Sure if you string up a 30 scale bass with really thick strings you could get low, but try playing it. Carl thompson once mentioned in an in depth interview that in his mind the single thing that most affects tone is scale length.
Acoustic 370 or Ampeg SVT450 + Ampeg Heritage 410 and SVTDI, Ampeg B15N
Ibanez Lawsuits, Framus, ErnieballMusicman, Custom Builds.