If you want to learn how to use a traditional gunsight reticle to judge distance go offline. Get behind a drone and see how it relates to the width of your reticle's circle or a horizontal line in the reticle. Most reticle circle's diameters equate roughly to a 39ft wingspan at 200 yards. So a radius is 400 yards. And so forth. Then turn off icons offline and start shooting drones.
The british M2 ring is 70mil wide with an upper and lower vertical line that stops at the ring. The horizontal line passes through the ring and has a space in the middle with a dot. The space in the center between the horizontal lines is about a 39ft wing span at 350-400 yards. The width of the horizontal space could be opened or closed to account for range based on a 39 ft wingspan.
The german revi ring is about 70mil. Three of the horizontal line ticks are about a 39ft wing span at aprox 350-400 yards. By the way I found out recently that hub mounted 109 cannon were set at 400 meters along with hood mounted MG. FW the 20mm in wing root and gondola were set to 550 meters. If you use a traditional Revi gunsight the multitiude of tick marks make lots of sense with those settings. Has to do with the slow rate of fire and high slow lobbed trajectory in the german cannons.
The american N9(P51B), L3(P38J,L) and N3-B(P38G,P39,P40) ring and dot is 70mil. The ring is a 39 ft wing at about 300-350 yards.
The american Mk8 has a 100mil ring and an inner 50mil ring, full cross with lower 45deg rays. The 100mil ring is about a 39ft wingspan at 333 yards. 50mil about 600yards.
The russian PBP1 has an 80mil ring with a 56mil inner ring and full cross. The inner cross has hash marks at about 5mil. Inner ring is a 39ft wing at about 350-400 yards.
The japanese Type98, Type3 are based on an F6F, P39, P40 wingspan at 300 yards.
See a pattern emerging.....many players do not realise that they don't track the other aircraft visualy. They track the icon and it's yardage counter because it's big bright and red. During close in dogfights they rely on the big red icon to save them from having to pay very close visual attention to the aircraft they are fighting until trigger time. This reliance on the red yardage counter for gunnery solutions is part of the reason some players have trouble with no-Icon mode.