Okay. *deep breath*
Because, I mean, I'm happy to discuss different cultural interpretations of gender and how ideas about gender identity and expression arise from a culture and its values over time, and how they can shift and change in response to different social pressures, and how this ties into creating systems of oppression in Western society and how those assumptions harm us, and how colonialism leads us to interpret gender in other societies through a Western lens and thereby misinterpret and misrepresent nuanced and different ideas of gender because it works from a faulty set of assumptions, and ways to combat that all day long, but...
This is not that. This is very 101 stuff that you got a lot of good answers to in your previous two threads.
You seem to be conflating gender-coded expressions (masculine and feminine) and roles with gender identities (man and woman), and misattributing how power is distributed based on these, and interpreting everything from the assumption of a Western cultural lens as default.
You're certainly not the first person to do this. It's a common mistake to conflate gender expression with identity, and on top of that misunderstand how a culture places values on both of these things.
Earlier waves of feminism attempted to create power for women by demonstrating that women can fulfill masculine gender roles and expressions. Women can wear pants. Women can be as hard-ass and aggressive as men. Women can succeed like men by expressing or emulating masculinity. However, while this made strides in gaining power for some women, in doing so, it also tacitly supported and affirmed the underlying assumption that masculine-coded expressions and roles are superior to feminine-coded expressions and roles. It supported the cultural notion that masculinity is better, more desirable, more powerful than femininity.
More recent waves of feminism have recognized this and sought to address this devaluation of femininity by explicitly questioning these assumptions, and re-emphasizing the power and value of feminine-coded expressions and roles.
However, both of these things are tangential to the other problem: the assumption that expressing masculinity is being "like a man" and expressing femininity is being "like a woman". This has led to frustrating characterizations of masculine women as being like a "man in a dress" (a common critique and characterization of 1-dimensional "action girl" heroines) and feminine men as being like women (a common critique and characterization of 1-dimensional gay male characters in romance genres). While there is often an underlying writing problem these critiques are getting at in terms of 1-dimensional characters and failure to consider differences in how men and women (and masculine people and feminine people -- because there is a difference) interact with the world, these characterizations are harmful and reductive in their simplicity and how they uphold the "masculine = male" and "feminine = woman" assumptions. There is a cultural hard link between gender expression and identity in Western society that we are finally trying to disentangle, and recognize that expressing femininity doesn't necessarily make one more like a woman, nor does expressing masculinity make one like a man. This addresses your question of "turning women into men". It's a question based on faulty assumptions.
And finally, there is this pervasive assumption that masculine and feminine coding is based on an underlying human truth that isn't merely cultural. And while I think there is some merit in how some aspects of masculinity and femininity may be common across some cultures, and there is room for discussion and analysis there, any such generalization runs the risk of misinterpreting other cultures and their nuanced ideas about gender through a Western colonialist lens, and often serves merely to further some biased agenda about what masculinity and femininity mean in the interpreter's own culture.
From there, you also run the risk of conflating cultural ideas about gender expression with cultural ideas about power. Is a particular expression or social role powerful because it's coded as masculine, or is it coded as masculine because it's considered powerful? This is the other central flaw in your question. Step back and consider how much of one's ideas about what is considered masculine and feminine are conflated with ideas about what is powerful, and who holds power in a culture, and how that power is created. This is at the heart of your question. And it's not as simple as "masculine" traits being powerful, but rather there is the possibility that we consider a trait "masculine" because we have been conditioned to associate masculinity with power, and a different culture might consider the same "masculine" trait as feminine-coded, or consider the same "powerful" trait as a sign of weakness.
A simple experiment to get an idea of how malleable our ideas of gender are, and how intertwined with systems of power they are: tell someone how desirable it is to be a good father, how it's important to serve as a role model for young boys, how powerful the father figure is, and then ask them whether being good at raising children is a desirable masculine trait or not.
Both power and gender are deeply cultural, and if you're creating a second world fantasy, you aren't burdened with Western society's ideas of them (though you should certainly write with your readers associations in mind).
Ultimately, you need to ask yourself not merely how to make "femininity" powerful, but what is power, and what is gender, in doing so, learn to question your assumptions about how these things are intertwined, and how much of that is based in deeply-seeded cultural ideas about who has power, and how they keep it.
It's not as simple as upper body strength and uteri.
