Though biology dictates men to be stronger, society does not value physically strong women outside of the Olympics and other sporting competitions (which still aren't as encouraged growing up as it is for boys.) The example from my own life that comes to mind is a microwave.
I used to work customer service in retail. In both our and the cashier job description, we are required to be able to lift fifty pounds. Yes, they certainly make exceptions. However, one morning, a lady came in wanting to return a microwave that she had trouble getting into her car in the first place. She was an old lady so I could see her having an issue.
I called for my manager and told her if it weren't for the fact I was alone in my department, I would have been glad to have followed her out and brought it in for her. She heavily implied that she didn't want me to in a nice manner. My manager that morning was an older Filipino man at least four inches shorter than me and arguably the same weight. She was so ecstatic when she said he could help her. I could lift that manager and have no problem carrying him out of the store in case of a fire.
And that's what I find is a decent metric that shows the dissonance. I have been around kids where the adults around are surprised that a little girl can pick up a boy her size (when there is no gender difference yet.) People are skeptical when I tell them I can pick up someone twenty pounds heavier than me. I am average in height and size but people, both men and woman, don't have a metric for the average woman's capabilities. There's also the disconnect that babies and kids actually weigh something and are held for long periods of time, sometimes while multitasking, by their mothers (and fathers but that's not the point.)
We are growing closer to a point that society should recognize what a woman is capable of but the fragility veil is still there. I do agree that in a world of magic, they should be equal and it's stupid to exclude women from military ranks. That will change as soon as Selena becomes queen, whether the dusty lords like it or not; it's difficult to argue when you have a woman that proficient with a sword and willing to use it accompanied by a powerful man who loves her to pieces.
Don't know about that, lady Illia... The "woman weak" stereotype isn't some made up stuff by society. It's biology. But in a word where men and women may have equal access to magic, imo, that shouldn't exist. Just like in our modern world, you don't have to be a big and strong knight who can brawl for a day straight anymore to fight a war not because people changed their mindset but due to the fact that a wound from a kid with a modern firearm at the right place can render all those years of training useless in a split second. There were many female soldiers in world war 2 some of them fighting inside tanks. That frail looking witch alone is undoubtedly stronger than an entire army of burly men in that world. No way anyone who wants to win a war would impose such a stupid restriction.