An averaged aim fov for games that have multiple aiming fovs, but can only set one sensitivity. Have it in the list to choose from, not replace the existing options.
Like CS:GO, you can only set a global zoom ratio, but there is 4 different zoom fovs. 10, 15, 40, and 45. An averaged FOV would be 28 Hdeg 4:3.
For COD, it is consistently 65 (pistols), 55 (smgs), 50 (assault rifles, red dot sights), and then a wide range of different scope fovs depending on game, but 55 and 50 are most important. Averaged FOV would be 52.52691 Hdeg 4:3.
For Battalion, there are lots of different fovs, but for 105 hipfire fov, the averaged FOV would be roughly 72.7 Hdeg.
For Fortnite, you have zoom sensitivity handling assault rifles and snipers, 15 and 40 FOV. An averaged FOV would be 27.83632 Hdeg.
You don't have to include all possible fovs, as some can be outliers.This would be a good compromise when you can only set one zoom sensitivity which handles lots of different fovs.