However, the prevailing conditions i.e. the fact that she was under her own power makes no difference. It is what happened to the bow section relative to the stern setion after they part company that matters.
Of course it makes a difference. It is still unclear when exactly the Edmund Fitzgerald broke apart. It has been suggest that the bow hit the bottom while the stern was still outside the water causing the ship to break. Even if that was not the case the weather conditions are not the same as when Titanic sunk.
It's like comparing apples with pears in this case.