>biggest tank battle in ten thousand years
>heretics prepped for this since Perturabo invaded in M39
>caught the defenders below full strength
>number of heretic tanks, not even tank crew, outnumber defenders by more than ten times
>losses on the heretic side were total
>losses on the defender side included a few assault marines and a scratched paint job on their mobile fort
I don't know who came up with this plan of attack but they clearly have no business doing planetary invasions.