Soldiers are people meant to overcome other people. Victims are those who are overcome. Useless henchwomen are both. Because they are meant to be instruments of force, they are made mockery of when proven helpless. Because they are plentiful and weak they are expendable to their leaders. They are amusing to their enemies. The henchwomen are pawns: being sacrificed is the part they play.
My fancy is uncommon. Few understand it. Villains as victims? Why women? Why not? Seriously: why not? Should every antagonist be formidable? Heroes have their damsels in distress. Why should villains not have their useless henchwomen? Sex and violence are the vim and vigor of adventurous fiction. Useless henchwomen are but passive partners in sensually violent character interactions. Why not? I ask but my question is never answered: why not?