I'll have a go.. I think i'm right but I might not be
9! ways to interchange the head,
9! ways to interchange the shoulders,
9! ways to interchange the bodies,
9! ways to interchange the backpacks,
9! ways to interchange the legs
So there are ways to interchange all parts except the hands.
Now, for the hands,
There are 9 * 4 = 36 hands in total to distribute out.
But there are only 9 * 2 = 18 possible places for these hands.
There are 36 possible hands for the first position, 35 for the second, 34 for the third....
So the total ways to arrange the hands is
So the total ways of interchanging, configuring, arranging etc. everything, is