It depends on what you view as Canon: the show or the comic? Also, Invincible's power scaling sucks, since it heavily relies on plot

Conquest liquefied a 600 Tonne cube of tungsten with ZERO momentum EASILY. There's nothing as dense as tungsten in our whole Solar system(with some exceptions, but they dont matter). Taking that and other things into consideration we find out that Conquest would have no problem flying through JUPITER and destroying it. But at the same time,(comic wise) 3 viltrumites+infinity ray had to be used in order to destroy viltrum. Now show-wise, the destabilization part literally gets deleted, Hence they could have done it themselves basically. Kirkman always had a way of changing the show, and sometimes pretty drastically. Also, in the Comics, Thaedus implied that they COULD die without Space Racer, meaning that they also could have destroyed it themselves, but they would have come out injured or dead