Pick Many fixed and variable correct answers

As you've discovered, graded questions require the user to select the specific answer(s). They don't allow for "any one of these" options. 

You could get what you want using a disguised pick-one question. Put those buttons (one for correct, one for incorrect) off the slide. When the user submits their answer, use a trigger that changes the appropriate button to Selected, with conditions to check whether they selected a correct set of wires. 

This post is about providing partial credit for multiple-response questions, so it's not directly related. However, its demo file might be helpful for understanding what I mean by using a disguised question slide: TIP: Give Partial Credit on Multiple Response Questions | Articulate - Community