That is not completly correct.
Catholic standard positions on the ordinations was that that a bishop is a true bishop if:
1- who order him is a true bishop(s) (ok)
2- the rite is formally correct
3- the intention of the ordaining bishop(s) is to do what the Church believes
About the rite, the lack of some sentences in some anglican rite is quite weak: not only because the form of the sacrament changed a lot during the centuries, but also because the Church have the power to 'sanate' some missing in the form (a doctrine very similar to the orthodox idea of 'ecomony', even if more limited)
In fact the focal point of the Apostilicae curae was the missing of intention to do what the Church believes. But this is very dependent from the very bishops who performed the ordinations. We cannot read in the mind of them. But we can anyway rely on the word of the pope, and so consider such ordination invalid.
Orthodox add (as far as I know) two other conditions for the validity of the sacrament of the order:
4- the existance of a Church in which the ordination is done
5- the correct orthodoxy of the bishops consacteting and consacrated
The first condition is, IMO, really appropiate because the the Church is an essential part of the priesthood, that is not a proprerty of someone. (well..there are many single person, out-from-the church, that are ordained 'validally' as bishops..quite ridicolous)
The second condition is not really considered by catholic, because it do not marry well with the principle "ex opere operato", and because it is not easy to define the border of a correct orthodoxy.
But we know that know the most of episcopal, and also some lutheran, bishops can trace their ordination back to some catholic or orthodox bishops of the XIX - XX century, and so out from the Apostilicae curae. Are they properly ordained? who know. IMO Probably not, and because of mainly above point 5.