The older ranch stock tends to run low pitch with long uninterrupted slopes. Low pitch is unforgiving in wind-driven rain, because water has more time to work sideways under a lifted tab. When hail bruises the mat on those roofs, the resulting soft spots hold moisture and the deterioration accelerates through the following freeze-thaw cycles rather than stopping when the storm does.
The newer infill houses fail differently. Steep, cut-up roofs shed water fast but they concentrate it, and everything depends on flashing and valley detailing. Hail damage on those homes frequently shows up as split ridge caps and damaged pipe boots and vent housings before it shows up in the field. Adjusters sometimes scope a partial slope on these houses; when the damage crosses planes, a partial does not restore the roof as a system, and that is an argument worth having with documentation rather than volume.
A Stacker analysis of NOAA data found Cook County averaged roughly 78 severe weather events per year between 2010 and 2020, including about 17.7 hail events annually. In a village with this much age variation, that exposure history produces a genuinely wide spread of roof conditions.