Great if you are plannig to ambush your attacker or for some reason expecting an assault....
The "interview" stance derives it name from the fact that Law Enforcement Officers use some version of it while they are talking to unknown subjects.... it keeps the gun away and, in one way or another, prepares the hands to move effectively.
Of course, the fact is that if someone ambushes
you, you are going to flinch and react from
that position, not your judo-dojo-academy-square-range ready position.
I like Mr. Farnam, but I think that he is teaching from a very old playbook. Is his interview stance better than standing around with your hands in your pocket? Yeah. Does it look ridiculous after about 4 seconds unless you ARE interviewing someone in an official capacity? Almost Certainly. The world is not a dirt berm with paper targets in front of it.
Try preparing yourself to react from a variety of "non-violent postures" (BTCMS Terminology)... arms folded (not crossed!), hands on hips, scratching your chin, adjusting your glasses, etc, etc... these are the positions that you are actually likely to be in during that "any moment" when you could need to react. Incorporate a flinch before you go to gun or block a strike and you are truly preparing yourself for surviving an attack.