There are a couple of issues here.
First of all, I think Aces High has what I rate as the best combination of flight model and gunnery model I have every seen for a WWI flight sim. If anything is to be a good indication of how "hard" it really was, I think AH is a decent simulation in that regard.
Second, net lag plays a part in the difficulty of HO attacks, or lack there of. Namely, because of net lag, you will see the other guy fly directly toward you for longer than he really did, and vice versa for him. It means that even though he pulled off and avoided the head-on at 500 yards, because of lag you don't see him turn at all. The end result is that he is "easier to hit" because lag shows him going straight longer than he really would.
Of course there is always the "no fear of death" as well. In real life, ain't no way no how a Zeke would try to HO my Jug in real life. However, in AH, I see it quite a bit. (I love when they try that...)
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Lephturn - Chief Trainer
A member of The Flying Pigs
http://www.flyingpigs.com "A pig is a jolly companion, Boar, sow, barrow, or gilt --
A pig is a pal, who'll boost your morale, Though mountains may topple and tilt.
When they've blackballed, bamboozled, and burned you, When they've turned on you, Tory and Whig,
Though you may be thrown over by Tabby and Rover, You'll never go wrong with a pig, a pig,
You'll never go wrong with a pig!" -- Thomas Pynchon, "Gravity's Rainbow"