It's not common sense to set a merge alt for most people, believe me. Most people you get in the DA (think Cmustard) look for any advantage they can get and will do the lowest sort of things to do it. Like pacerr saying use 50 fuel while he grabs only 25% (my personal favorite). Anytime someone insists on 50 fuel you can almost guarantee that's what's going on.
And to A8Tool's comments... in a duel why would you ever be chasing a guy? And what does stick settings have to do with anything? The plane can only maneuver as much as the airframe allows, a certain stick setting can't make it do one bit more. Hell Lazer and Nilsen fly with a mouse... think their "stick settings" are uber? And they would own 99.9% of the AH population in a duel.
The reason there are rules for duelling is because it's supposed to be a gentleman's sport of fairness in setup to see who the better pilot is. A test of skill, not dweebery. If you object to all of these things, I can only come to one conclusion, and this is based on 10+ years of flight sim experience... the only ones who ever reject all the rules are the ones who have to have an unfair advantage to win. And why? Because they have zero integrity and just suck at fighting.