Hi @dperez13 ,
I see you have posted several similar threads on this People Picker Combo box, have you solved this issue?
Generally speaking, if the Combo box allows single selection, it requires Record type data, and if it allow multiple selections, it requires table type data but you can populate a single record into DefaultSelectedItems property. For your scenario, if you would like to auto populate the allow multiple selections Combo box with some other People Picker, you can use the selections from that control directly:
If(Form.Mode = FormMode.New, [{DisplayName:..., Claims:...},{DisplayName:..., Claims:...}], OtherPeoplePicker.Selected)
Best regards,