I just read on Wikipedia (cuz I always Wikipedia shit) that Heihachi was actually supposed to be Cloud Strife, but the deal fell through at the last minute. That would have been much cooler ...depending on how much emo one can handle.
Goddammit Squeenix, that would've made a huge difference back then (no matter how much of a Nightmare/Siegfried clone he probably would've been). The FF series was a peak popularity back in 2003 and Cloud would've easily dominated the competition (and made the constant Link vs. Cloud debates from that era even worse (and the inevitable L-Block upset all the sillier (and the final 'Settle it in Smash('s DLC)' even more hype))).
Still, Link was easily the most popular South California guest due to being at his peak popularity and being all about weapons and tools (seriously, bringing a bow/bomb/boomerang/hookshot to a knife/sword/whatever fight; his bullshit was much cooler than Yoda's stubbiness or Dork Apprentice' Force powers meter management), Heihachi bringing no real weapon to a weapon-based fighter (and not being interesting enough to make his bringing of his fists to a knife/sword/whatever fight as badass as it sounds on paper), and Spawn being locked to the XBLOCK (and being a Comic Fanservice character in a Videogame Fanservice role).
Edit: I forgot about Necrid being Teh Apprentice of SCII. Namely because he was king of low effort in that game (no weapon model, and was basically Killer Croc with a Glowy Chest Rock). He's also why Spawn wasn't nearly as great as he could've been (because they were both McFarlane character designs, so you got Chinese Knockoff, Low-effort Spawn (Cape sold separately), no matter which version you got).
Why Double Post When I Could Just As Easily Make An Edit To A Tangent With Something Actually Relevant And Even Unexpected But Well Timed Edit mkII:
http://www.siliconera.com/2017/12/07/soulcalibur-announced-vi-announced-game-awards-2017/Guess what came back from the dead over half a decade later (and its been over a full decade since SCIV came out, what the shit)?
Also, they seem to be ditching the timeskip. I suppose its for the best since a lot of the SC Gen 2 characters were pretty weak sauce overall (also, kinda ironic since SCV's deal was them trying to tone down the T&A that had taken over the series by that point, whereas the last five years of gaming have caught up to SCIV's levels of debauchery instead).