So guys? any help here?

Basically, you want a brain unit that drops a brain(not dead) when its dead. Am I right?

Yeah. Exactly like that.

function Destroy(self)
MovableMan:AddParticle("Unpinned Brain");
end

That's basically it, though you do have to define it and the position and etc etc.

Hmmm... so make the attached brain actually an attachable, and if the actor that it is attached to it is destroyed, make a new brain in its stead?

Some question though...
let's assume the first (carrier) actor and the soon-to-be brain are both in the brain category. When the game starts I put the carrier actor (with the brainlike attachable) in as a brain that moves around. Then if it's dead it'll 'make' a new brain. Question is, will the game end first if the carrier actor dies?

On destroy self should activate within the same sim update; if you're lucky the brain will spawn and CC won't notice. If you're not, it won't.

So, this is kinda unreliable?

Good... it'll make gameplay more interesting.
Will try this out soon, and if it works I'll release it after tests.

Make its head gib into a dropship on your team and have the brain on your team in the dropship's inventory. Tadahhhh.

Well, the 'brain' is not in the head, but rather attached to the torso. So you're saying to create a dropship that has the same sprite as the brain and the attachable, and have it pop in the game when the actor's dead?

Have the body gib a dropship, and in the dropship's code just AddInventory the brain.