That is a typical Zoe Williams article, she never presents indepth arguments about anything but simply record lists of things that seem to support the opinion she has already formed without any analysis or consideration that the topic may be a bit complicated. (I do think there are things that the royal family need to take seriously in this whole mess but I don't think that article is good at highlighting them.)
One single example, because I haven't had my coffee yet,
"The charge of racism, however, will not evaporate: it is not just the extraordinary crassness/white supremacist bouquet you can smell in that Archie remark"
She is hanging serious accusations of racism on a remark that a) has never been repeated publically by anyone involved and b) that Harry himself denied was racist. The rest of the article is the same, taking things that are written about, however vaguely, in this book and Spare as completely accurate because they feed into her dislike of monarchy.
To go back to the thread topic, this is where I think Scobie has sabotaged himself. What he writes is so badly written and biased that it can't really be used to seriously analyse the monarchy. Plus his track record of lying about Finding Freedom and the Dutch situation means that he is not really seen as a good reliable source anyway.