In a contract action brought against alleged joint debtors: The plaintiff need not prove their joint liability as alleged in order to maintain the action; The plaintiff may recover as in actions in tort against one or more of the defendants who are shown by the evidence to be indebted to the plaintiff; and Judgment shall be entered in the plaintiff’s favor against one or more of the defendants as fully as if the defendant or defendants against whom the plaintiff fails to establish a claim had not been joined in the suit.