Good question. I was thinking about that death roll earlier (Edge + Edge). I am not sure there should be modifiers to that. Here is why:
Coydog with 2 Strength has 9 Physical damage boxes. At capacity, a full Physical track would give her a -3. With an Edge of 1, she would get no dice. That's bad but it gets worse.
Sledge with 8 Strength has 12 Physical damage boxes. At capacity, a full Physical track would give him a -4.
Even if they both had 2 Edge, the stronger, tougher character is more likely to die.
I don't think I will be enforcing wound modifiers on death tests.