People are understating how bad this is. This is definitely +1, maybe even +2 with customs off for Rosa, because if Rosa starts camping G&W has very little options. In my top 3 worst G&W MUs for sure.
Let's look at pros and cons from G&W's side. Customs on.
Pros:
-Bair can launch Luma if he lands while doing it
-Toot toot can kill early if you catch them at just the right percent, depending on ceiling position
-No hitbox on Recovery=free bonus damage offstage, possibility of gimp (depends on stage)
-Trampoline Launch kills lighter characters pretty easily
-Short Order Chef can stun Luma
-9
-Custom Stars can be bucketed, but the result is sadly not an OHKO, and Bucket has a lot of lag if it eats something but isn't filled
-Upsmash kills pretty dang early, is safe on shield, and armors through and punishes dair
Summary: basically, G&W's strength in this matchup is that he won't have a TON of trouble securing the kill at high percents, like he does with a ton of the cast.
Cons:
-Rosa's crazy aerial range almost completely negates his aerial abilities: Rosa nair outranges and outprioritizes everything, dair's disjoint loses to Rosa's crazy long disjoint, uair only suspends her in the air and doesn't beat her dair, and G&W nair just doesn't work.
-Luma messes with G&W's grab combos, which account for 50% of his damage(like he can even get a grab with that darn bodyguard in the way)
-G&W only has one option to get up from ledge on jabbing Rosa, Fire, which can be reacted to with upsmash
-Speaking of jab, Luma's jab finisher kills G&W at like 100%. ONE HUNDRED PERCENT. JAB. Heck, a little later and even dash attack will kill.
-Uair has the chance to kill obnoxiously early, multiplied by the fact that G&W is third lightest in the game.
-The range advantage is just TOO big. G&W has no approaches that are safe and knock Luma away, so he'll have to take damage just to kill Luma. He gets spaced out incredibly hard, even against non custom Rosa. Every move G&W has, Rosalina's version has way more range. Meaning G&W cannot win the neutral with Luma there unless the opponent makes an egregious mistake
-non-Short Order Chef is just USELESS here. Luma can just meatshield it if anything
-G&W's OoS is pretty weak against characters with long ranged aerials. No good aerial out of shield meant RosaLuma can pressure G&W at little risk
-How will G&W kill a Rosa who sits in shield past percents where toot toot isn't true anymore (which is like after 80%)? The lack of kill throw is a huge problem.
Summary: So, while chances are G&W will have to get a read to even kill, he's gonna have a hell of a time racking up the damage too. Stage choice is going to play a huge role in this matchup. The unbalanced neutral means Rosa will almost always have a damage advantage, and she will usually win a last hit situation, since G&W will need a hard read while Rosa just needs to find a good punish opportunity.G&W's formidability offstage and the strength of his actual killing tools keep it from being unwinnable however.
Customs off: +2 Rosa
Customs on: +1 Rosa
