This is honestly a pretty huge mismatch. Brightburn's best destructive feat is destroying a building complex (so Large Building to City Block level) and blitzing normal human reactions (so likely Subsonic speed). Meanwhile, Hancock is anywhere from Town to Mountain level (depending on the timeframe) based on him defacing a
sizeable portion of the moon and is pretty solidly Supersonic from his ability to create sonic boombs just by moving. Add in Hancock having a far better healing factor, and the results are pretty much set in stone.