I don’t think the author is trying to make the point that the UK and France were right or wrong to pursue appeasement. Rather he is trying to debunk a very spec

I don’t think the author is trying to make the point that the UK and France were right or wrong to pursue appeasement. Rather he is trying to debunk a very specific argument that they went with that strategy in order to buy themselves time to mobilize. In fact, they were not significantly more prepared for war in 1939 than in 1938 and ended up on worse footing, according to his argument. So I think your point stands, but we can also question when someone justifies the appeasement strategy by saying that UK/France needed more time to mobilize. In fact, they were probably more taking a gamble to see how things would play out.