I've posted this link before, but worth repeating.
https://www.whatsbestforum.com/threads/harbeth-monitor-40-2.25222/
Scroll down, and down, for the photos.
Frankly, this may be pushing it, but as just said, with a minimum of 2' behind and 2' to the sides, I'd seriously consider the 40.2's, as those Thiels weren't exactly small.
I've heard both, and to me the SHL5's have a different acoustic presentation (though some would tell you they are more size-appropriate for your room), and I preferred the 40.2s.