Best Christian arguments against transgender care and transitioning?

Let me preface this with a few things. I'm in favor of transgender care and trans people being able to transition. I don't think it's a sin, and I don't think the Bible talks about it at all. More than that, I find the most common arguments about it (He made them as man and woman or that Deuteronomy passage about crossdressing for instance) to be terribly weak and unconvincing arguments.

So ignoring the most common and in my opinion flawed arguments against trans issues for the sake of this topic, what do Christians who oppose transgender care and transitioning feel are the strongest arguments against it? I've never seen an argument I've felt is persuasive. Still, I'd like to see those arguments, since I feel that seeing them is intellectually healthy. One doesn't choose an opinion and then become a stone, utterly unchanging, after all.

I know this can be an issue that has strong opinions, so I'm going to try to post with grace towards everyone here, no matter what I think of their posts. I'd ask anyone who posts her to do the same to the other posters here.