Potentially high firepower from Star Wars Galaxy of Adventures.

[griffinflyer]

https://www.youtube.com/watch?v=VCSKGz4Pb-E

At 00:34 we see large explosions in front of the Death Star. Having analysed the video extensively, I have concluded these explosions must be located very near to the Death Star, and each are likely at least a mile across. This is based on the fact that we do not see starfighters engaging each other, all we see are explosions, meaning that the combat is occurring far away. The correlates to what the movie shows- combat is localized to near the surface of the Death Star. Armed with the knowledge that capital ships did not participate in the battle, it would seem logical to conclude that some starfighter weapons (likely bombs or missiles) carry megaton level firepower. This conclusion is also supported by the short story “Star Wars The Force Awakens: Tales From a Galaxy Far, Far Away”, in chapter 14 of which, we are told the ENTIRE Death star seemed to shake- from the point of view of a man deep inside it. On top of that, we see the Death Star shaking in the film. Shaking the Death star with mere fighter bombs is an impressive feat.

[The Romulan Republic]

While I don't doubt that there are fighters in Star Wars that can carry megaton-level missiles, given the stylized nature of most animation, firepower calcs from it are dubious at best- especially if they contradict a scene shown in live action.