If there are three major sides, but one side is missing, how many sides are there now?
What side is missing? Egalitarian isn't a "side", it's not a position, it's a philosophical framework that one applies to societal problems. It's not exclusive to gender issues, it's a concept that can be applied to all facets of society.
This is just as true(if it is true at all) of egalitarianism and feminism. Or of the MRM and Feminism.
Sure, but something just not being mutually exclusive doesn't tell us much about how the numbers break down in reality. Many things aren't mutually exclusive but that doesn't mean that they're commonplace. While it's true that feminism and egalitarianism aren't mutually exclusive either, most feminists don't use the term at all because whatever variant of feminism they label themselves as encapsulates and expressed their beliefs. I don't think that I've seen or met one feminist in real life who's ever heard of egalitarianism as a label, let alone use it for themselves because academically it's a trend of thought, a general principle that's incorporated into many different ideological views which basically states "I believe in equality of some sort". Most, if not all contemporary political theories are egalitarian, the difference is that for feminists their "equality of some sorts" is tied up with and explained by the brand of feminism that they endorse.
But even still, if this sub is any indication the majority of feminist thought is considered to be decidedly not egalitarian. I've seen people say "If more feminists were egalitarian like CHS I'd be a feminist" or other statements to that effect, showing a clear distinction between most of feminist thought and egalitarianism. What CHS terms as "gender feminism", I think that most people here would consider to be non-egalitarian feminism. So what this ends up amounting to is more a dichotomous situation in that one singular respect, that on average egalitarians and MRAs on this sub - though not necessarily the same in all facets of their beliefs or positions - tend to align on their stances and attitudes towards feminism and feminist views.
Now, even looking at the examples that femmecheng used, they weren't just MRAs either. So while we can say that theoretically there can be three distinct viewpoints in the sub when it deals with feminist issues, views, or beliefs the lines of division between those three areas gets replaced by something a little more binary. There's definitely a distinct us vs them vibe going on in this sub when it relates to womens issues, and I tend to think that this has more to do with the gender demographics than the labels that we apply to ourselves. We're focusing on the breakdown of labels when I think what we should be focusing on is the gender makeup of the sub itself. At the end of the day people are more sensitive to issues that they can personally face themselves and tend to misunderstand or downplay the problems that they don't or won't. With the demographics being so skewed towards male you'd expect to see a male bias in the sub regardless of ideological positions because that's just how it works. So male issues get promoted and supported while womens issues are treated with skepticism or dismissal. And that, I think, is the dichotomy and why femmecheng can legitimately say what she said without reprisal.
Besides, you are one of the people who equates the groups already, so I don't see why you are even bothering to defend this. You think it is okay to do.
I don't equate them totally, I've just noticed that many egalitarians and MRAs often don't have much differentiating themselves from one another. And because they're not mutually exclusive labeling oneself an egalitarian doesn't actually exclude them being MRAs either.