The user claimed "40%" as the likely "true" number of trans users. 60% is definitely a majority. I believe it's 100% possible that there could be "false-trans trolls," though I also believe that doubting someone's trans identity on the grounds of being unpleasant or confrontational is transphobic and identity erasure. People's self-procclaimed identity is the only identity that matters, if you have to judge everyone on whether or not you're a "true-trans" that gets into transvestigation territory, only in the opposite direction. It's harmful to actual trans individuals, a sort of "guilty until proven innocent" rhetoric that I personally don't agree with. Again, I myself am cis, so the actual lived experiences of trans individuals, and thus their perspectives and views, may be completely different.
I do disagree about horseshoe theory. People being far-left vs far-right are similar only in that they passionately believe in radical politics. The actual views, however, are staunchly different. Leftism is fundamentally anti-hierarchy, anti-imperialism, and anti-capitalist, whereas rightism supports and upholds hierarchy, Imperialism, and Capitalism. These are extremely incompatible and dissimilar ideas, one side rejects racial hierarchy while the other upholds it, one side supports trans liberation while the other demonizes them. Horseshoe theory is nonsense.
Your final point is completely divorced from the topic at hand as well. The claim by the subject of the OP is that people on hexbear "white knight" trans identity and use it as a shield, despite being cis, on the grounds of being confrontational. This is a claim without evidence, just vibes. Regardless of how unpleasant a troll may be, their identity should be respected, even if they are trolls that should or should not be blocked. A trans troll is both trans and a troll, their identity shouldn't be called into question because they happen to be a troll.