Does Z Vegetto needs to be > Base Baby Vegeta?

[GreatSaiyaman123]

I mean, Goku seemingly only lost to Baby Vegeta because of stamina issues with SSJ3. So when Baby becomes Super Baby Vegeta, could surpassing Goku be what led him to wield the strongest Saiyan power?

 

[SSJ2]

I wouldn't really say that's true. Base Baby Vegeta more or less was able to tank SSJ3 Goku's attack without taking damage. Before Goku regressed back to Base, he was shown effortlessly evading his attack. Baby didn't look anything close to serious during that fight, which is also supported by the fact that he later told Goku that he would draw out their fight to make him suffer more.

Goku even said that he would need SSJ3 just to withstand Baby Vegeta, he never showed confidence that he'd be able to beat him outright after Baby powered up. He was banking on being able to drive Baby out of Vegeta's body somehow.

Episode 29
Time: 4m35s
Context: Goku just attacked Vegeta to no avail
Goku: "Once I've defeated you, I'll beat the eggs out of everyone else!"
Vegeta: "Once the eggs have been implanted, you cannot beat them out of someone!"
Goku: "In that case, I can still drive you out of Vegeta! I should be able to drive you out!"
[ ]
Vegeta: "You sure you can do it?"

Episode 29
Time: around 8m15s
Context: Vegeta has just powered up
Goku: "He's got awesome power! If I'm going to withstand him...I'll have to do it at Super Saiyan 3!"

Goku was at a level where he could hold his own against Base Baby Vegeta, but he was already surpassed prior to his transformation into Super Baby Vegeta.

 

[Captain Cadaver]

There's also these statements that make Baby Vegeta > SS3 Goku even more apparent:

Episode 29
Time: 9m25s
Context: Goku's punch did little damage to Vegeta
Goku: (to himself) "It looks like he's more than an even match for me, even at Super Saiyan 3! The power of Baby and Vegeta combined...I never thought it would be this great!"

Episode 29
Time: around 9m50s
Context: Goku is losing control of Super Saiyan 3
Vegeta: "What’s the matter, Goku? Is that all the power the mightiest Saiyan has?"

That said, I'd say SSJ Vegetto definitely has to be above Base Baby Vegeta for the statements to make sense, otherwise there'd be no reason to wait that long to have made a statement on the strongest Ki he'd sensed a lot sooner.

 

[Pyro]

You're both right.^

I'm not sure the argument that Goku only lost due to lack of stamina has any stability. His stamina loss didn't kick in until after he'd fought Baby for a bit, and that short fight showed him as being unable to inflict any meaningful damage or get Baby to take him seriously. His statement that Baby was "more than an even match" for him should already solidify that Baby had the power advantage regardless of stamina issues. Would the fight have gone on longer had Goku been in his adult body? Probably, but there was never any doubt who the winner would have been.