[teshigahara]

No, this doesn't make sense in the context of Japanese.

One of these signs is written right to left:

https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQdiwLY...

https://auctions.afimg.jp/h1085974646/ya/image/h1085974646.2...

Which one is it? There is no way to tell unless you already know the characters. Unless someone could read the existing signs they would almost certainly assume they were left-to-right and make any new sign like that if they only had the characters to copy.

[freeopinion]

I appreciate what you are pointing out here. I agree with you that getting it just right would be a challenge.

Did you happen to see the lathe? I ask you, which would be more difficult to get right in the smallest detail?

While most Allied soldiers would not be literate in Japanese, that doesn't mean they would all be completely ignorant, either. It just takes one to know enough to ask about character order.

While I agree that it was high risk, I'm willing to believe the people who were present when they say they pulled it off. Sometimes we dodge bullets without even knowing they were fired.

[livueta]

As someone who both a) does precision fab work as a hobby and b) made the somewhat unfortunate decision to memorize many thousands of kanji without caring about stroke order: it's harder. Sorry. 100% agree with the parent: even though I can read Japanese at a fairly advanced level, having not properly learned stroke order is a massive bitch. I can't handwrite for shit, and that's obvious to me and anyone else who can read Japanese of any degree of complexity. It is so many orders of difficulty above "ask[ing] about character order" that I can't even begin to verbalize what a category difference of difficulty it is. Handwriting Japanese that looks correct to a native reader assumes years of naturalization.