I think it is Full HD because of the wording
Alchemical: States you make a lesser simulacrum (You can have many of you running around at 1/2HD)
Doppel: States you make a simulacrum of yourself (not a lesser) (You can only have 1 running around cus it is you)
Greater: States you make a simulacrum (Now you can have many of you running around at higher HD)
Each one kinda does something different.
Doppel; to me is a very limited clone since it is for self only.
AS/GAS: Is more for building your alchemist army to take over the world (MUUAHAHAHAHA).
