Are you suggesting that writer should create their characters with some quota in mind?
I don't really understand why people view balancing the gender of characters on screen as enforcing a quota and why whenever anybody says this they say it because they view quotas as bad - every time - lol! It's half and half. Why is there so much gnashing of teeth and beating of breast about such a simple concept. Equality means equal - roughly equal numbers in equally varied positions. It'a a laudable goal, it isn't happening, so let's think of simple ways to make it happen.
As I said before, you can flip a coin or just alternate the gender of the supporting characters as they crop up in the script. In some ways coin flipping or dice rolling is better as it creates more variation on screen at any one time. If Ensign Doohicky isn't going to spend the next scene in bed with Scotty, determine their gender randomly. Why not? I don't think STiD would have been so different if Admiral Marcus had been Carol's mum based on a die roll.
And as I say, this isn't a general thing, this is about Star Trek.