Holy cow, I wrote a book!
The principle of "garbage in, garbage out" applies to Unicode collation.
If you hand it a meaningless string and ask to compare it to another
meaningless string, you get meaningless results.
I am not a Unicode expert; I just play one on the web.
A real Unicode expert is Michael Kaplan,
explanation of how comparing invalid Unicode strings result
in nonsensical results
I strongly recommend to those who attempt to generate
random test strings in Unicode.