I don't have other accounts, but still matched at 85+% accuracy for a half dozen accounts. Seems I don't have very original thoughts or writing style.
My guess is that people from the same region and similar background will have more and closer "alters". So, if you are Californian-American then there is many people that will speak similar to you in HN. If you are a Satawalese speaker then you may be quite alone in your own group.
(The Satawalese language has 460 speakers, most of who live in Satawal Island in the Federated States of Micronesia.)
You couldn't have just picked a European country, you had to flex on us with Satawalese? :)
It's a fingerprinting tool, not a profiling tool. You can't draw such conclusions from it.
What a profiler would do to identify someone, I imagine, requires much more. Like the ability to recognize someone's tendency of playing the victim to leverage social advantage in awkward situations.
85% is surprisingly high for fingerprinting, hence self-deprecation over insulting the author by poking at efficacy. I wouldn't have expected my Australian spelling, Oxford comma, or cadence to be anything close to the Californian Rust enthusiasts I apparently match against. Especially as there's no normalization happening - so even the Burrows-Delta method shouldn't match my use of "gaol" or "humour" that often.
But, limiting to the top couple hundred words, probably does limit me to sounding like a pretentious dickhole, as I often use "however", "but", and "isn't". Corrections are a little too frequent in my post history.
I'd expect things might be a tiny bit looser with precisions if something small like stop words were removed. Though, it'd be interesting to do the opposite. If you were only measuring stopwords, would that show a unique cadence?