That's one perspective, that Bill is stronger. It's worth noting that Blood and Thunder specifically involves a Bloodlusted, powered up Thor fighting a reluctant Bill. Despite that, Bill gains the upper hand at least once in the story, knocking Thor on his back and then pausing to ask Thor to yield. Which gives Thor an opening to lay into Bill.
What I'm saying is it isn't a clean win.
Another perspective is the Stormbreaker series features Bill taking out that celestial body, and then an earth like planet getting destroyed later. The latter is treated as a much bigger deal. Bigger boom, bigger splash page, more damage to those involved. So one could argue the scan you posted probably wasn't as big a planet.