Hello Alex,
I'm no expert in the font field and for that reason I rely on information that I find online.
Which means to me that your information is valid like anything else I find.
Here is a link to a blog which might interest you:
And I have setup my browsers accordingly.
I would expect that 'sans', 'serif' and 'mono-space' function as system wide aliases in any application, but my experience is that I get better results when I configure any browser by naming the correct fonts.
By the way, I also find 'opinions' of people who don't like Ubuntu's font rendering.
Enjoy your system!
Wilbert van Bakel