For what little it's worth, I'm inclined to agree with Mr. Ashey. To my eye, guardrails on 1/700 scale (or smaller) look fine - especially if they're made to "sag" in the right places. On 1/350 scale they start to look like what they are: pieces of metal tape with holes in them. And at 1/200 scale I'm afraid my willing suspension of disbelief would be seriously taxed.
It seems like it might be practicable for some aftermarket manufacturer to make a photo-etched metal set on 1/200 with individual rail stanchions - and holes in them for wire guardrails.
On the other hand, I see Gold Medal Models offers a couple of sets of photo-etched parts (including railings) for the Nichimo Yamato. I haven't seen these particular products, but everything I've ever seen with the GMM label on it has been first-class. Mr. Perry, the owner, frequently updates his products when new information or technology becomes available. It's quite possible that those railings are superior to anything that was available when Mr. Ashey's book was published.
Youth, talent, hard work, and enthusiasm are no match for old age and treachery.