With depth perception and two off set eye's the sight wouldn't be a problem.
It was the same, and the F-4F-3 in a swarm of Zero's convinced the Navy deflection shooting needed to be vastly improved. Deflections were all your going to get.
USAAF's N-9 was 100 mil, also known as the 100 mile sight, 50 mils or half the sight translated to 100 miles per hour. For every 100 mph your adversary is traveling, 90 degrees at full deflection, you add another radii distance to your lead.
For angles you compensate.
90 - 60 degrees, full deflection
60 - 30, use 3/4 of full deflection
30 - 15, 1/2 of full deflection
15 - 0, 1/4 of full deflection
Being a 100 mil sight, a fifty foot wing span will fill 50 mils, foot per mil, if you know the type and wing span or fuselage length, you can range it.
Posted charts that might interest you here, homework was already done long ago.
http://i135.photobucket.com/albums/q...00-25-3527.jpg
http://i135.photobucket.com/albums/q...00-25-3526.jpg
Just remember center the ball, and the Army considered it a waste of time to fire banked beyond the first tick on your bank and angle indicator, at least early in the war.
Navy's Mk-8, the lines are 300 mils, outer circle 200, inner 100. The little lines within the inner 100 mil circle are 25 mils. Length of one complete unbroken line 125 mils.
Use the 2/3 rule with this sight, enemy traveling estimated 300 Knots, use 200 mils lead. Use the same deflection rules as above, but remember this one is set up to use knots as reference speed.
Both sights basic rules, enemy diving estimate for maximum combat speed, and for continuous climbing figure 3/4 of normal cruise speed. Know your opponents type of aircraft speed abilities, tail high, he's fast near combat speeds, tail low cruise speed. Don't know how well that's modeled in game. Study the enemy you expect by dimensions, wing and length, and speeds, than you can range and gauge him.