Ranch houses and attached roof sections
A ranch house is long, low and mostly roof when you look at it from the street, and its shallow slopes shed water more slowly than steep ones. The additions that make these houses practical, the carport over the driveway, the garage tied in later, the covered patio, each add a roof section with its own slope and its own connection to the main house.
None of that is a problem by itself. Plenty of south-side roofs are in fine shape, and a house's era says nothing certain about the covering on it today. What the layout does mean is that a proper look at one of these roofs covers every section and every joint between them, not just the biggest slope.