In short - since ME is not my point of interest - I do not think you should readily dismiss both the book and the article. I find them fairly accurate in their assessment of the nature of the problems (which I can confirm from the reports Warsaw Pact/Soviet advisors made during the Cold War) even if the broader conclusions seem a bit too careless (not sure they are - political correctness is a cancer).

I have a copy of 'Arabs at War' at home, and dare declaring it 'at least useful'. Yes, some of conclusions are 'fairly (actually, 'rather generally') accurate' - but many are not, and there is plenty to criticise, too.

First - and for me: major - issue I've got with that book is that it's based on absolutely no Arab sources. I think there're perhaps one or two citations of any kind of sources of reference at least leaning on Arab sources in all of its 700+ pages (from memory).

On it's own, this wouldn't be that much of a problem - if a) that book would at least lean on official Israeli documentation, or b) certain Israeli authors who actually did research with help of Arab sources (could cite few names here, but I doubt they mean anything to anybody, and - AFAIK - not one of their publications are available outside Israel or in other languages than Hebrew).

But, it is not. It is largely based on various 'memoirs' of leading Israeli commanders. So, what one gets to read there is what these commanders want us to think or recall about these wars - and surely anything else than 'all that's important to know'.

This in turn means that a study of its chapter on (just for example) Egypt in 1973, needs quite some additional reading. Here I would recommend at least Asher's 'Egyptian Strategy for the Yom Kippour War', or even such 'work of love' like Carlowitz's 'Egypt at War, 1973'. The former is largely based on captured Egyptian military documentation from 1973, and on studies of related military publications; the latter is foremost useful just in order to show how much is missing - i.e. how much remains unknown about this war - in such works like Pollack's book.

But even all of that is 'just a little bit of help' simply because even if one reads all of that, one has still missed so many really excellent books about Arab militaries - available in Arabic only. These are ranging from Mustafa's 'The Fall of the Golan' (which, should it ever get translated and published in English, would probably result in lots of revisions of usual stories about the Syrian front from June 1967), to Hammad's 'Military Battles on the Egyptian Front, 1973'.

Whatever... again: 'Arabs at War' might be something like 'useful introduction', and cannot be outright dismissed. If for no other reasons then because it does contain certain statements that are of high value (like author's endnote about 'precision' of the Israeli air force on the Golan front in 1973). But, I can't agree with most of those who are usually describing it as 'indispensable'.

I am also not aware of the "stark differences" between SA and Qatar.

Neither am I. Actually, if one asks Iranians, their opinions are directly opposite to what the OP indicated.

Or is it simply that SA is significantly more incompetent than Qatar?

The entire story about Saudis being 'incompetent' and 'proving' this during the ongoing war in Yemen is simply propaganda and misinformation.

Actually, Saudis proved far more effective and combat efficient already during their first taste of Yemen War, back in 2009-2010. Sure, they made plenty of mistakes back then too - and suffered correspondingly: if one talks with them, they're not even trying to hide this. On the contrary, they're pointing out they've learned their mistakes (and love to add such 'details' like that up to 5,000 of their officers, NCOs and various other troops were subsequently court-martialled, including a few of 'princes' and 'royal highnesses' etc., and that the entire military was - more or less - reorganized ever since).

But, as explained already here,

As the military analyst Tom Cooper has noted, the Gulf coalition underestimated many factors working against it: the resilience of Yemeni army loyalty to Saleh and the Houthis, the effects of terrain, the Houthis' fighting capabilities, and the complications posed by al-Qaeda in the Arabian Peninsula and Islamic State operations in southern Yemen's liberated zones.

I.e. my conclusion is: it's not the military that proved incompetent, but (as so often in the last, say, 70 years of Arab military history) its political masters.