1 is questionable, in part because of the claim that we don't know how under reported it is in 2. But also because there have been studies going back to the 70s suggesting that most violent relationships involve mutual violence, and the ones that don't aren't a large majority of men abusing women. For example, the woman who founded the first women's refuge in the UK had written that many of the women entering her shelter were as violent as the men they were leaving, giving a number a number that was pretty close to numbers Strauss, Gelles and Steinmetz came up with from their research in the 70

Those studies get questioned or minimized not because they have particularly bad issues with how they are done, but because the field is essentially subject to ideological capture and research that contradicts the goals of the activism at the time is worked against.

There's also some playing with terms and definitions that works against men in this kind of thing. To use a trans example, all women in the UK who rape are trans - this isn't because trans women are particularly likely to rape, but because rape is defined in the UK as requiring the perpetrator to penetrate the victim with the perpetrator's penis, which means cis women are incapable of "rape", but if you're a TERF and need something to support your point... For an example regarding men, Mary Koss (a prominent sexual assault researcher, enough so that you almost can't talk about the topic in the US without touching something descended from her work) was asked a question about men being raped by women about a decade ago in an interview. She responded with incredulity, asked how would that even happen, and when given an example who had been drugged into compliance was told by Koss that that wasn't rape, but "unwanted contact" and in other places she's made a point about the importance of keeping rape a word for female victims because men just don't feel hurt or shame in the same way.

Or NISVS where you see a couple of interesting things. One is playing with definitions where if a man copulates with a woman against her will it's "rape" but if a woman copulates with a man against his will it's "made to penetrate", with the latter being a subcategory of "Other" so as to obscure any kind of direct comparisons between them or that the two are as similar as they are. You also have this clearly demonstrated phenomenon that they seem to actively avoid discussing where previous year rape numbers are pretty similar (if you consider being "made to penetrate" equivalent to "rape") but in lifetime numbers men's reporting drops off drastically. I suspect this is caused by men not categorizing what happened to them in this way, in large part because they get told again and again that it doesn't count, that they were lucky, or similar until eventually they believe it.