When Baby arrived on Earth, did she think that Vegeta was the most powerful character in the Universe?

[SIAD]

Baby when he owns Goten, thinks that Vegeta is the strongest in the Universe, because he is aware of the power gains that Vegeta had in those 9 months and not those of Goku. The same goes for Gohan, he is only aware of Vegeta's increase in power.

Baby knew the power of Goku Base (Post M2), Trunks SSJ2 (Post M2) and surely knew how powerful Super Hyper Mega Rildo is.

Also Baby when he possessed General Rildo, at least he knew the power of Goku SSJ (M2) and I think he was not aware of his very temporary power up as SSJ2.

Therefore Vegeta SSJ2 (Baby) is stronger than Goku SSJ (M2), all forms of General Rildo, stronger than Goku Base (M2), stronger than all Saiyans (except Goku from that point on).

 

[Boo Brand Milk]

Probably the strongest of what's left. Goku was not on Earth when Baby invaded. Having Tuffle prior knowledge also helped.

 

[Captain Cadaver]

He believed he'd be able to become the strongest in the universe by possessing Vegeta. Although he could've become stronger by possessing Goku, he'd rather possess Vegeta due to the irony of the Saiyan royalty that killed the Tsufurian King having his body bent to Baby's will as well as likely the Gotenks Boo-esque motivation of wanting to use that power to personally destroy Goku.

 

[Symbiote]

Did he not ask Gohan who was the strongest after possessing him? Or was that a dub only line?

 

[SIAD]

Gohan and Goten knew that Vegeta (Arc Baby) was stronger than in BoGT, instead they didn't know if Goku had gotten stronger in that time. That's why perhaps they thought Vegeta was the strongest in the Universe.

 

[Captain Cadaver]

Did he not ask Gohan who was the strongest after possessing him? Or was that a dub only line?

Episode 26
Time: around 6m40s
Subject: Saiyans
Baby: (to himself) "When I was with Trunks, I wasn't able to completely read his memory, but I can read Goten's. I see... There are Saiyans in Metro West, huh? And among them, the mightiest Saiyan is...Vegeta..."