Hobbes has two accounts of the ‘artificial man:
De Homine, XV On Artificial Man and Leviathan XVI Of Persons, Authors, and things Personated. That is the last part of De Homine and the last part of Of Man in Leviathan, so the idea of the artificial man has the same place in the construction of De Homine/De Cive as in that of Leviathan. In both cases, the idea of the artificial man comes in, partly as the the actor in relation to the author, which is taken as the model of covenant.
Leviathan brings in a complication about the actor not obeying natural law. This is to be blamed on the author, and it would be a breach of natural law for the actor to disobey natural law. This reflects rather oddly on the origin of sovereignty in the covenant that the multitude enters into in order to establish sovereignty. This set up is even more complicated when we recall that the covenant is between the members of the multitude and not between the multitude and the sovereign. In any case, it shows the importance Hobbes gives in Leviathan to the foundation of natural law and maybe a need to bolster the argument of De Cive with references to natural law. The Leviathan version also reinforces the idea of fictions and idols as artificial persons, which seems to both ground the idea of the sovereign leviathan and undermines ‘superstitious’ religious tendencies to believe some person or thing represents God. The account of the artificial man brings together a justification of representation and its rejection. If the religious fanatic is a false representative of God, may this not lead to a greater scepticism about all claims to representation, particularly the claim of the leviathan-sovereign to represent the multitude and to be God on Earth.