I'm not sure it's entirely true to say that TRA women or trans allies are not consciously working against the interests of women. I think many of them are. Some women who are fully onboard as trans allies think that feminism is a second- or third-order issue, that harm coming to some women is an acceptable sacrifice for a higher cause whether that is socialism, diversity, equity, trans rights, etc. The cause, whatever it is, is more important than women's rights.
Or they think that women's rights are sorted and the males claiming to be women are more vulnerable. That we are being selfish not to make room for the men who really want in. That the special males need our rights, services and spaces more than we do, in effect.
An example of this was a woman on twitter who aggressively insisted that in a time of hormone scarcity, men claiming to be women should take priority over menopausal women for HRT supplies because they needed it and we didn't. I don't have the link, unfortunately. This is our old friend #BeKind, of course, and this attitude is often combined with a naive belief in the sweetnaturedness and helplessness of all males who claim to be women. The kitten with one eye, or the dog at the kennels that nobody wants to adopt.
I think that's what they mean when they say that treating males claiming to be women as women takes nothing away from us as women - they mean that it takes nothing we can't afford to give.
Anyway, basically what I'm trying to say is that I don't think the focus of the "handmaidens" is women.