请教一个真题的倒装句型

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How explicit and consistent the symbolizing process was intended to be is a much thornier matter, but anyone who has more familiarity than a passing acquaintance with Dutch literature or with the kinds of images used in illustrated books (above all emblem books) will know how much less pervasive was the habit of investing ordinary objects than of investing scenes with meaning that go beyond their surface and outward appearance.

各位大神，我想问一下，how引出来的宾语从句后面怎么用了倒装？不是应该how much less pervasive the habit of investing ordinary objects was 才对嘛？
这里用倒装的语法依据是什么？