In every action or motion in which a decedent, if living, could be joined as defendant with another or others under section seven of this article, his personal representative may be joined with him or them, or with the personal representative of any one or more of them. In every such case in which a judgment is rendered against a personal representative, alone or jointly with another or others, such judgment, as to such representative, shall affect only the estate of his decedent, and shall, as to such estate, have the same force and effect as if rendered in an action in which such representative is sued alone. But nothing in this section shall prevent a plaintiff, at his election, from proceeding separately against the representative of any decedent.