Valentina Remenar's art for Tomax and Xamot was, like the brothers themselves, two halves of a unified whole:
But that layout wouldn't work on the GI Joe Classified boxes, so the art had to be rearranged so it didn't overlap the plastic window on the front.
If you can't see it, notice that on the full art, the small figures are directly below the large ones' heads, while on the final product the large heads have been moved to the sides.
Notice also that half a silver Cobra logo has been added to each box. When you stand them next to each other on the shelf, a full symbol! Fun!
Bonus: here's how the bros look on the normal ML suit body (courtesy Everett K. Ross):
Like Storm Shadow, the head can sit loosely on top of the body, but it won't attach in any way. This is also slightly smaller than their normal bodies, making the heads feel a bit oversized. Perhaps one of the other suits would work better.
I’ve seen the retro carded Hammerhead body for suited twins. Its a bit bigger than the Classified body but works visually better than the smaller ML MCU suit body.