Five layouts cover most desktop navigation needs. Horizontal global only is the simplest, one bar, best suited to shallow, broad structures with few top-level categories. Stacked horizontal bars add a secondary bar beneath the primary one, giving more room for categories without going vertical. Horizontal global with vertical local pairs a top bar for site-wide navigation with a sidebar for navigating within whatever section someone is currently in. Vertical global only puts the entire navigation in a sidebar, which suits spaces with many top-level categories or labels that vary a lot in length, multilingual sites, for instance, where translated labels can be unpredictable lengths. Vertical global and local nests both levels together in one sidebar, often with expandable sections.
The right layout usually reveals itself once you look honestly at two things: how many top-level categories the content actually has, and how much that number needs room to grow.
1: Horizontal global with vertical local. Twenty top-level categories with deep local navigation within each needs a layout that can accommodate broad global navigation while still giving each section room for its own detailed local structure, exactly what this combination provides.
2: Horizontal global only. Five service areas with minimal hierarchy is a small, shallow structure, precisely the case the simplest layout is built for, with no need for the added complexity of local navigation or a sidebar.
3: Vertical global only. Fourteen languages with unpredictable label lengths is the classic case for a vertical layout, since a sidebar accommodates varying label lengths far more gracefully than a horizontal bar, which has a fixed, limited width that long translated labels can easily overflow.
4: Horizontal global with vertical local. Three distinct audiences each with their own separate hierarchy benefits from a global bar that lets visitors choose their audience path, paired with vertical local navigation that then serves each audience's specific deep structure once they've made that choice.
For the news organization, horizontal global only would definitely not work. Twenty top-level categories displayed as a single horizontal bar would either crowd the available space unreadably or force many categories to wrap or truncate, this layout is explicitly suited to shallow, broad structures with few categories, and twenty is well beyond what a single horizontal row can present clearly, regardless of how the local navigation within each category is handled.