I don’t believe people could have been saved had someone else done more. There use to be an ultra traditionalist blog that thought Fatima was a fraud. Its down now and I never got a chance to read his whole thesis.
Pope Paul VI write in Apostolic Constitution On Penance, 1966:Christ, in fact, is the supreme model for those doing penance. He willed to suffer punishment for sins which were not His but those of others.35
35. Cf. St. Thomas,
Summa Theol., III, q. XV, a. 1, ad. 5. (Reply to Objection 5. A penitent can give a praiseworthy example, not by having sinned, but by freely bearing the punishment of sin. And hence Christ set the highest example to penitents, since He willingly bore the punishment, not of His own sin, but of the sins of others. )
We do read in the DIRECTORY FOR THE APPLICATION OF PRINCIPLES AND NORMS ON ECUMENISM:25. Because ecumenism with all its human and moral requirements is rooted so profoundly in the mysterious working out of the providence of the Father, through the Son and in the Spirit, it reaches into the depths of Christian spirituality. It calls for that “change of heart and holiness of life, along with public and private prayer for the unity of Christians”, that the Decree on Ecumenism of the Second Vatican Council calls “spiritual ecumenism”, and regards as “the soul of the ecumenical movement”.43 Those who identify deeply with Christ must identify with his prayer, and especially with his prayer for unity; those who live in the Spirit must let themselves be transformed by the love that, for the sake of unity, “bears all things, believes all things, hopes all things, endures all things”; 44 those whose lives are marked by repentance will be especially sensitive to the sinfulness of divisions and will pray for forgiveness and conversion. Those who seek holiness will be able to recognize its fruits also outside the visible boundaries of their own Church.45
They will be led to know, truly, God as the one who alone is able to gather all into unity because he is the Father of all.
vatican.va/roman_curia/pontifical_councils/chrstuni/documents/rc_pc_chrstuni_doc_25031993_principles-and-norms-on-ecumenism_en.html