Can an order appointing an administrator ad litem be substituted because there is an existing executorship?

In Mantle v. McIntyre, an order appointing an administrator ad litem had been granted when there was an extant executorship. The court held that the order should not have been granted saying, at 132: It is a statutory condition precedent to the granting of an order appointing an administrator ad litem that neither letters probate or letters of administration have theretofore been granted. Here that condition was not satisfied although it was made to appear that it had been. That order was therefore void ab initio The court also added (at 133) that the executor could not be added “because you cannot add something to nothing”. The court noted the case was not one of misnomer and said that the addition of the executor would be the equivalent of introducing a statute-barred cause of action because the limitation period had then passed. If the error had been a misnomer, then presumably, substitution could be considered.