From rough descriptions of the comics, they sound like they cover similar or same materials. Are they simply comic tie-in to prequel books? Or just happened to cover similar stories?
Found the answer in Afterword to "Earth Unaware".
The comics were Card's idea, and the books were an offshot of the comics, covering the same events in more details.
- First, Marvel did adaptations of existing Ender books as comics
- Then, Card gave them idea to create new comics (what would become Formic Wars series)
- Then, they wrote the novels, as planned:
So Scott and I had to make some concessions and exclude people and events from the comics that we knew would only exist in the novels
In addition, Card was Executive Director and Creative Director of the comics:
Found another canon confirmation that they are the same story, from Card's web site. He posts various reviews (under "Uncle Orson Reviews Everything" rubric) on hatrack, and has this to say about Earth Unaware Book:
Aaron Johnston scripted the Formic Wars graphic novel series (Burning Earth; Silent Strike) from Marvel Comics; now we're creating novel versions of the same story.