Let’s say Omni Man had a change of heart before killing the Guardians and decided to warn Cecil and the heroes of Earth that Viltrumites are coming. Would Nolan, Mark, Cecil, the Guardians and the rest of the heroes be able to stop the invasion? Assuming the Guardians are as competent as they are in the show and have prep time.
Hell no. >!Conquezt or Anisa take the Guardians out easily, Nolan & Mark early on at this point struggled with the Viltrumites on Thrxa let alone a invasion. And then Thrgg on top of it making minced meat out of everyone?!<
Even if Cecil knew of the >!equilibrium weakness and Robot was somehow able to create the armoured suits that emit that frequency, Thrgg seemed fine in handling that, the other Viltrumites too later on in the finale. They’d need the weaknesses Nolan discovered from his books and even then we’re talking about killing all the Viltrumites instead of redeeming them.!< I don’t see any world where Earth wins that.