Not so sure that your conclusions are as valid to WWI as they are for WWII. I can't really recall a very effective airfield straffing mission in the Great War. First of all they were not all that common (probably more common in BHAH than in real life). Secondly, twin rifle calibre weapons are just not that effective against ground targets - as opposed to, say, a battery of 8 .50 cal. high ROF guns on a P-47.
Finally, I don't see Rickitycrate's advice as being unrealistic (although it does go against a typical human nature response = SCRAMBLE) as it takes advantage of the natural disorganization of enemy a/c after the first sweep.