I think it's a little more complicated than that.... more akin to the Syrian civil war than the Second World War. As one example, what do you do with the Gay campsite who wouldn't allow trans-men to apply? What about when some lesbians say they are increasingly being pressured and coerced into accepting trans women as partners - then shunned for speaking out.
That's what makes this whole thing so complicated and nuanced. There are also those who tacitly enforce a cis-gendered world because that's their entire lived experience. My Mum is the example i used in this article, but I suspect many people over sixty haven't had this issue intersect with their lives in any meaningful way. They'd be more than happy to expand those boundaries - that's the generation that ushered in a great number of LGB rights - but perhaps they are happy about the direction of travel but not the speed. Labelling those people transphobic won't be helpful in the long run... they're potential allies being declared as enemies.
As for group three... a career in social work will tell you that predators come in all shapes and sizes. They come with their own complexities and have to be understood on an individual by individual basis. They can and will exploit loopholes in the law, that's what happened in Loudoun County - nothing to do with Trans-issues necessarily and everything to do with not considering the full implications of decision making.