That has nothing to do with the validity or invalidity of their orders.
A valid sacrament requires (one more time) valid form, valid matter, a valid minister, a valid recipient, valid ministerial intent (typically, the intent to do what the Church does; it doesn't imply orthodoxy of belief), and valid intent on the part of the recipient (in an adult, the intent to receive the sacrament). The history of the group the minister or recipient belong to doesn't matter, as long as they're validly ordained in succession from the Apostles.
Ludwig Ott, Fundamentals of Catholic Dogma, covers this extensively. (Ott was the standard text on dogmatics in the immediate pre-Vatican II era.)
I respectfully disagree and here's why.
"Despite the ongoing work of the ecumenical Anglican-Roman Catholic International Commission (ARCIC), in 1998 Joseph Cardinal Ratzinger (then the Prefect of the Congregation for the Doctrine of the Faith, and later Pope Benedict XVI) issued a doctrinal commentary to accompany Pope John Paul II’s apostolic letter "Ad Tuendam Fidem", which established penalties in Canon law for failure to accept “definitive teaching.” Ratzinger’s commentary listed Leo XIII’s Apostolicae Curae, declaring Anglican Holy Orders to be “absolutely null and utterly void,” as one of the irreversible teachings to which Catholics must give firm and definitive assent.[1] These teachings are not understood by the Church as revealed doctrines but are rather those which the church’s teaching authority finds to be so closely connected to God's revealed truth that belief in them is required in order to safeguard the divinely revealed truths of the Christian Faith. Those who fail to give firm and definitive assent, according to the letter, “will no longer be in full communion with the Catholic church.”
However, many persons, including Basil Cardinal Hume have suggested that the conclusions of Apostolicae Curae can only relate to the situation in 1896, and that the involvement of Old Catholic bishops in Anglican ordinations during the 20th century has re-established apostolic succession in that Church (along with a change of consecratory prefaces). Other critics argue that apostolic succession had never been broken in the first place, due to ordinations tracing back to Archbishop Laud as well as Archbishop Parker. The latter was alleged to have been a break in the chain of apostolic succession - an unofficial cause of concern to Rome regarding the validity of Anglican orders."
I also think it is helpful to read "On the Nullity of Anglican Orders, Apostolicae Curae."