in the Marvel comics, the nebulons had to be undergo heavy modifications such as having joints replaced and having reinforced skeletal structures so that they could contort easily when converting into their partners' heads. in Rebirth, however, the nebulons never had their bodies modified so that they could contort, and yet for some reason, when they're transforming, they seem to have limbs detached when they're transforming, and that's something that their Marvel counterparts could not do.

what's with that?!?

One of the reasons I liked the comic better was just for this reason: the Nebulans needed heavy surgery to be able to transform into the heads/guns/engines, unlike the cartoon.

Another thing about the cartoon transformation to head: have you noticed that the head transformed into the suit of the Nebulan, but the nebulan just sits in the head like it was some cockpit. Bit of a size problem. I liked how DW solved this (slightly based on the cartoon) that the suit was actually a lot larger than the Nebulan and he wore it like an exo-suit, only sitting in the main body controlling the suit.

Sorry? What do you mean exactly with this?

you'll have to see Rebirth pt2, especially the scene where Hardhead's head firsts transforms into Duros' armor.

Maybe the animators didn't want you to notice that the nebulons heads were going up their asses or something. Plus, i dont think open surgery on a cartoon character would go very well with the pre-teen group or younger. Something that graphic would not go well on a saturday morning cartoon.

The tv wanted it to make it simple to understand.