Oh yeah, I much prefer the G&W/C. Falcon MU over the Pacman/C.Falcon MU.
Mr. G&W destroys him imo. Falcon doesn't beat G&W in the neutral, which you can't say for most of the cast. G&W outprioritizes Falcon all the time. This probably goes in my top five G&W matchups because you can afford to play REALLY aggressively, so it's a lot of fun. G&W can finally use his disjoints for spacing in this MU. Since Falcon's hitboxes are on his body, just wall him out with disjoints. Also, you can duck telegrab, and his dash attack is punishable, weakening his approach options. He's gimpable too. One of G&W's biggest advantageous MUs. I'd even call it 65:35.
Anyway, discussing Peach, eh?
Well, I've been watching Dark Peach's stream, and I even got an online viewer battle, but it got really laggy in the second stock, so it wasn't a very good sample. Dtilt can put a damper on floating approaches, and Turnips aren't that good, so this is another MU where G&W can kind of wall the opponent out and somewhat prevent free approaches. Fire is also an effective tool to escape her devastating strings. So we have some stuff on her.
On the flip side, she kills G&W sooooo early. An errent fair at the ledge will kill under 100%, and a dash attack doesn't kill much later. The threat of getting hipchecked will break G&W's fragile zoning capabilities. She has no trouble securing the kill. Edgeguarding her is difficult because of her great recovery though. Punishing her attacks on hield might also be a hassle.
All in all, I call it close to even since G&W does OK in the neutral against aerial-heavy opponents, but Peach can destroy the poor guy if given the opportunity.
45:55 in Peach's favor