Bnz IMO if you can't see if he's right side up at 400 yards then
A your monitor is too small
B your resolution is set too high
C Both!
Gunery is determined on your FE, if you see a single dot, its going to be very hard to hit it. But
if you have a larger monitor, and lower resolution setting, so you see a bigger dot, its going to be a lot easier to hit.
The higher you set your resolution, the better things look, and the smaller the planes get.
What is a single pixel dot at 800 yards in 1600x is 4 or 8 pixels at 800x.
But don't take my word for it, check it out yourself.
Key is to find a balance that you can live with, and still see to shoot.