This morning on Facebook (which I've taken to calling "Spacebook") I ran across an interesting question.
"So here's a question for writers and readers: I'm working on a mystery story and when I showed the first part to my writing group I got the comment that there are too many strong, tough female characters. One person said, "You have three female characters, all ninjas" (that's an exaggeration, but they are all physically fit and tough.) Does that strain credibility? And if so why? No one would think twice about a story with a lot of tough male characters. What do you think?"
The answer to this is complicated, and can't be fully explored on Spacebook. It's just not the right place. The answer runs the gamut from social expectations to psychology to random musings of my confused mind. It even runs into research I did (many years ago, and just for myself) that breaks down media into easily digested sound bytes.
In the words of Indigo Montoya, "It is too much. Let me sum up."
First, the gender of your audience. If your primary audience is female, you are going to be able to get away with more strong female characters. However, the audience for action adventure is going to be assumed to be primarily male, which means that strong male characters are going to be expected. Your writing group will break this down without thinking about the ramifications.
Second, the social expectations of your audience. The media society we live in has a certain set of expectations. These are things we don't bother to think about, for the most part. We don't even blink when a woman is a reward for the hero's actions--it doesn't even occur to us. It doesn't occur to us that the "strong" female character is a caricature of feminine graces with cleavage. These are things we've been led to expect. Ladies are to be rescued and the men do the rescuing. And if you don't believe me, honestly view the last ten movies you watched, the last ten TV shows you watched, the last ten books you read, etc. Likely one of the ten is going to have a strong female character, if that. Even those that have a strong female character, she's generally a caricature or a physical reward for the hero, and shows more cleavage than muscle.
It is possible that your entertainment preferences are different than most, so in that case go with the ten top grossing films, top ten most popular books, etc. These are what the majority are seeing and absorbing. Believe me, these things set up expectations and if those expectations are broken the readers are going to notice that something's wrong--even if they don't understand why.
The society we see in the media frowns on a physically strong woman. People have certain expectations when they read a book or watch a movie, and if you break those expectations you're going to get a reaction--probably not a good reaction.
Third, the writing, and this is where I'm going to spend the most time. Just about anything can be made to seem normal and acceptable if you write it appropriately.
Are the characters real? We are used to seeing female characters who have only one or two attributes--she's a good mother and a book-keeper. She's strong and spiteful. She's got cleavage. But unless we're dealing with a romance, male characters are nearly always fully nuanced. The female characters are there only as an accent for the male. People tend to write this way without thinking about it.
In order to create believable female characters, they need to be at least as fully nuanced as the male. They need to have the same level of introspection, interests, flaws, idiosyncracies, etc. Their challenges need to be fully realized and NOT dependent on the sub-plot of the men around them. If there is a romantic element, they still need to be people in their own right and not just a satellite circling around the male MC. If the female MC's only attribute is that she's strong, your readers will get bored quickly. If there are three MC's who are equally strong in the same ways, it's going to come across as three of the same person, and your readers will pick up on that. They will likely key on the things that the characters have in common, and say "You have three female characters, all ninjas" when that may not be the problem at all.
The second thing to be focused on is balance. If the main characters are all female, all strong, etc, it's likely to come across as a feminist commentary. You need male characters who are strong as well, even if strong in different ways. If you have no male characters, your story will be of interest to very few--see social expectations, above. Women expect to see both male and female characters. Men expect to see male characters. In order to appeal to both, you need both.
You'll need to write differently and with more awareness in order to make this situation work.
Third, are you over-emphasizing their fitness? Strong characters don't need to say all the time that they're working out or flex their muscles continuously. Let their actions stand in for telling. If you tell your readers more than once that this woman is a weight lifter, it sounds like you think your reader is stupid. If we watch her lifting weights, and part of the story takes place in a gym, and she has a weight-lifting trophy in her room, all of these things add to that aspect of her character. If she's a tai-chi instructor, that tells us something about her level of fitness without beating your readers over the head with it.
In my years doing manuscript evaluations, as well as writing groups and critique partners, I learned that the problem is not always visible. When someone says that there's a problem with a book, I need to take a look at the situation and determine for myself what aspect of my writing needs to be adjusted. If someone tells me that a character is "too strong," is that individual seeing the character's strength, or strength in relation to another character (is another character too weak?), or is there too much "telling" in relation to the character's strength, or is it a reflection of something else entirely?
Even the most obvious of critiques doesn't always pinpoint the precise problem. It's my responsibility, as an author, to identify the true problem and correct it. Often it's something tiny--a word choice, or a situation that needs to be restructured.
The situation is complicated, but once you identify the problems with the writing (what makes them come across as "all ninjas" when that wasn't what you intended) it will most likely resolve itself.