I’m going to disagree with the premise of this topic... but only slightly.
Many NFL stadiums are in the middle of giant parking lots with few significant buildings in their immediate area. Even those not so are typically domed (Toronto, New Orleans come to mind immediately). That’s not universal (Bank of America Stadium in Charlotte is within a roughly 1000 feet of a high-rise building), but it at least reduces the options.
Baseball stadiums, however... a lot of those are built in downtown areas amidst high-rises - with many more home dates to choose from.
Many stadiums are not a closed circle, but have separate upper decks with major gaps. Some stadiums I can name have clear street-level views of upper decks through these breaks. Line of fire, no need for long-range plunging fire. I only wrote this indirect plunging fire scenario because an average knucklehead can’t easily get the math, ballistics and trajectory just right on a first try. But there are MANY other ways an average knucklehead can do it, but I’m not putting them into the body of my main text to be a guide book.