The weakening strike is applied at its maximum level.
That's not true. The weakening strike is applied at the level it would be applied at if cast by the hero. And Orcs will always have it at the level without skills, as Darkness cannot be learned (just in case, Dim Darkness does not affect the strength of the weakening strike).
Plus, the bonuses from Blood Fury will replace the defense.
Plus, the bonuses from Blood Fury will replace Fire Wrath, Cursed Lands, and the Dim effects themselves.
Longistics can be omitted.
Dim Chaos and Darkness can be omitted.