I suppose [...] it should be safe to apply the later (unrelated) styles earlier as well. [...] I'll look into making this a bit smarter

Here's a screenshot of Chrome's profiler UI for this pageload (showing only "rendering" samples).

Here's a screenshot of the Firefox profiler UI, BTW, with me hovering the first of the blue restyle bars. As you can see, it shows "42ms Styles", and there are at least 5 such restyles shown in the profile.