As far as I can see, the Funchal/Porto Santo argument is irrelevant. The aircraft wasn't near either airport. The nearest was Porto, an excellent decision by the F.O.
BTW, for outsiders who may be on here, in most airlines (certainly the ones I have worked for) the F.O. is trained to exactly the same standard as the captain. Less experience perhaps, but no less capable.
Having said that, yes, Funchal is captains only.