Not sure where you got your "GNU Coreutils" from....
Years ago, I used UnxUtils. Reason? Just because I came across it first. And I liked that it, running on Windows, could handle that platforms path delimiter \
just fine... Later, I noticed that some if its tools didn't really work in all details/cli-switches like I needed them (and was used to from Linux). Also, I experienced some crashes. (Don't ask for details, this is fading memories.) Moreover, these tools didn't seem to be maintained any longer.
Then I searched for alternatives. I came across the GnuWin32 package. This seemed to me to...
(a) ...be better maintained (some tools get updates from time to time);
(b) ...contain some more of the GNU and other Free Software tools than UnxUtils does.
Though it's an annoyance to me that some of the GnuWin32 utils insist on /
for path separation (some others handle both just fine), I've still clinged to GnuWin32.