It shows the “equal” does not necessarily mean “same”.
True, in reproduction, which is a biological matter, only a man can get a woman pregnant; he contributes sperm to the union. Only a woman can be gotten pregnant by a man; she contributes ova to the union. Both share equally in the responsibility of creating life, and the end result is that they are both responsible for the child’s well-being; they both share the ministry of parenthood. They do not have identical functions, but they exercise necessary and equal functions at the same level. This is how genetics work. This is scientifically verifiable and observable.
But here we’re talking about a purely sacramental matter. Currently “equal” men and women are not permitted to receive an equal number of sacramental graces. (7 vs. 6) And because of this, women are excluded from exercising necessary and equal functions at the same level as men in the Church. This should scream injustice to all Christians. Even if you don’t care if women received Holy Orders, you should be angry that the Church loses out on the gifts and ministry of countless women who are barred from serving (with an equal, but not “same” sacramental character) those necessary functions at the same level as men in the Church.
To the OP: Please don’t use the following argument. I’m not a logician, but a developed common sense tells me that it is fallacious:
“God designed the world such that only women can get pregnant. So ‘Duh!’, only men are allowed to be priests. QED”
Which makes about as much sense as:
"God designed the world such that motor oil reduces friction in automobile engines. So “Duh!’, you are only allowed to drive on the right side of the road.”
Our friends in Ireland, Australia, NZ, UK, and elsewhere will laugh at this, because they know that driving on the left-hand side of the road works perfectly well, it is an arbitrary system that evolved as the popularity of driving cars rose and the popularity of riding horseback waned, and has nothing to do with the natural laws of physics (or biology).