This is a fun, silly topic. You have my blessing to treat it as an on-topic distraction until Sora arrives.
So, I trust
official height and weight (5' 9", 187 lbs) more than most game stats. Most are old, debatably non-canon, or just obviously wrong afterthoughts. I'm going to use Ryu as my baseline, 187 lbs = 103 smash-weight.
If smash's "weight" is linear, that means:
is 214 lbs
is 194 lbs
is 192 lbs
and
are both 189 lbs
is 178 lbs
are both 174 lbs, which I leave without further comment
and
are both 170 lbs; those big heads sure are dense (Toon Link is 165 too)
is169 lbs, suspect
is 161 lbs, also suspect
is 160 lbs,
super suspect
is 158 lbs, even though he is supposed to be 107 lbs! In Smash 4 weight, he would have been 149 lbs.
is 147 lbs, less than she supposedly is.
is 143 lbs, about 75% of what he probably should
is 153 lbs, while
is 142 lbs; Zelda's thick dress and giant jewelry being 11 lbs more actually is pretty reasonable.
is 145 lbs while
is 196 lbs... much more questionable. The Power Suit is supposedly 200 lbs in canon, not 50. Samus herself was supposed to be 190 lbs, but the ZSS character redesign kind of killed that notion.
is 185 lbs, much less than his 230 in canon though nothing as bad as Samus.
is 156 lbs, way more than a dog (or duck) of that size should weight.
is 143 lbs, versus a canon value of just 13. But then you remember that Pikachu is also only supposed to be 16 inches tall, and the Smash Pikachu is scaled up 2.25x to a size that rivals the biggest breeds of dogs. (
Much chunkier than Duck Hunt!) At this size, his canonical weight would be 148 lbs, making Pikachu's weight actually one of the most reasonable on the roster. Similar calculations apply to Jigglypuff.
is 211 lbs, very close to his canon value.
meanwhile is 140 lbs, a huge difference from his canonical value of 269. But I suppose if you describe it as 16% of a Steelix, it's not that low. Greninja is also half the weight he is supposed to be, and Ivysaur's canonical weight is just stupid. The point is, Pokedex weight were guessed by a 10-year old and don't matter.
is 192 lbs; if you scaled up the actual real-life ROB 7.5x times, it would weight more than 2000 lbs. It's a rather dense toy! Our version could be made of much lighter materials, but also needs, uh, rockets, fuel, and lasers.
is 231 lbs, which is probably half the weight a male gorilla of his size should have.
tops us out at 245 lbs, also comically low even after his weight ballooned in every version of Smash.
My conclusion: Most the weights work out surprisingly well, but "weight" seems to almost be a sort of "density" that excludes height. All the tall characters--heavy or light--have lower weight values than guessing their pure mass would suggest. (And short characters, especially humanoids, have more.) When you add in that gravity itself is not only strange but different for each character, the very notion of "weight" as it is to us becomes sort of funky.