Where I work, we have new manuals coming out shortly which do have overweight landing corrections for failures and also handle multiple failures.
I always found it strange that for a non-normal you didn't have to do an overweight correction.
I ran a couple of scenarios and found with the new tables. For a normal(?) overweight landing you may actually need less distance if you use auto brake medium instead of max manual. This is because auto brake will not wait until the nose wheel is on the ground before it starts braking (according to a PowerPoint presentation which I assume is an Airbus presentation)
I only found the new manuals by digging around the company's website after reading this thread!