Then stat them up as Commoners.
There's no need to differentiate between the miniscule differences of a "strength-based commoner" and a "dex-based commoner". They all have +0 in every ability and skill. If one is a blacksmith, give him (or her) advantage. If another is a basketweaver, give her (or him) advantage. Simple.
The point is that it was a long time ago the rules proscribed strength differences between the sexes.
If you want to describe the male commoners as stronger and the female commoners as faster, that's your call and I have no beef with that.
But you're going further than that - you're encoding gender into the stat blocks, and I'm calling you out on it.
There are no specific rules that say men are stronger than women, these are NPCs, player characters don't have to adhere to them. You can have a female player character with a strength of 18, but in this world, on average women won't be as strong as men. Player characters don't have to be average. As for stat blocks, I figure I'm not going to bother, the character sheets have all the information you need to use them as NPCs, their purpose is to add a layer of realism. Women warriors are unusual, they are above average, is that a problem? A woman who picks up a sword and wants to be a soldier has got to accept that in the ranks they will be out numbered by men, that is just how it is, right or wrong. NPCs and PCs are different. With PCs their are no rules separating the sexes as far as combat stats go, and if your player character encounter some human NPCs, they might want to know if they have names and what gender they are, so the players can form a picture of them in their minds, thus making the game session seem more real to them.
If you have an army of soldiers where exactly 50% of them are women and 50% are men, where does this happen? Not in the real world. Not in the United States, not in any country I know of. Some women want to be soldiers, but most women do not. I'm not saying they shouldn't be, I believe it is up to them, that is just my experience after talking to many women. I've talked to a few female soldiers, and I can tell you that it was really special to meet them, I respect what they are doing for the country, and I appreciate their sacrifice. I am just trying to be realistic. Medieval Europe was a certain way, that is history, I can't change it, but I am trying to bring out a little of that atmosphere, it adds to the drama more, than to have unrealistic absolute equality between the sexes in medieval times. I am sorry, but there is something unusual about a woman wearing plate mail armor on the back of a horse, it is the exception to the rule that draw attention and makes people famous.
This is a site rarely seen in the middle ages, this is Joan of Arc, most women didn't do this, but Joan did! is it wrong for me to acknowledge that fact that this is unusual? Should I have half the knights in my campaign be women? What do you think? In my campaign unicorns do exist, just like women warriors in a suit of plate mail, are they a common site? Not really, but that makes them all the more special!