Where their outfits are similar but different...
I am afraid I do not see it. I am really looking hard right now, but all I see are that the shoes have straps on one of them and the gloves are different. That's maybe like a 3% alteration of the same outfit
You really need to create different designed outfits for them. Not just the same design in different colors. Basic elements can be the same, like, they can maybe have the same gloves or the same shoes, but not the other way around. To me this looks like the same Knuffel was used over and over again and super tiny alteration were added.
I see the same Knuffel 3 times with just different pigtails.