If "WE" is invalid then why not "ALL" rather than "MANY" in the consecration of the Mass?
Change one word, how cunningly evil! I urge you to STUDY http://promultis.blogspot.c...
Ave Crux
Because this the words which follow "This is My Body" are not necessary to the "Form" of the Sacrament. If a Priest -- such as on a battle field under fire, or in a prison camp celebrating Mass covertly -- were simply to say "This is My Body" that would suffice for the Consecration. The words which follow are not considered part of the Form of the Sacrament by the Catholic Church.
How many invalidly baptized over the 14 years Springer served in Detroit? How many invalid sacraments by Fr. Hood?
If he has used the proper formula, his baptisms are valid, because anyone can baptize.

However, other sacraments are invalid.
In all their masses, for example, people have eaten only bread.