Conservative AM Darren Millar said a ranked list would make it clear "who has the final say" about whether someone's organs can be taken if they have not opted outof the donor register.
He also points out that it will soon be easier to register a society, although the government stopped short of doing away with the registration process altogether.
And there may be renewed calls from Labour peers for the Department of Health to publish its risk register - the document setting out its assessment of the risks of the NHS changes in the Bill.