It´s very well possible to get you enemy off your tail. Granted: It´s not super easy and often risky, but it makes fun. I remember occassions in my Stuka where I just turned off the engine and made a very tight turn. The enemy fighter was to fast and overshot me and suddenly he was in front of me. Wiht other aircraft you can outclimb your enemy, although you have to make sure there is enough distance to begin with between you and your foe or you end up as a slower target. Also you can dive and rotate and change directions to confuse the guy on your tail. Plenty of possibilities.
I did not say it's not possible. As I said, better climb, speed and turn can always save you. But when you have a skilled pilot with an equal plane behind you it is very hard and it's good that it is. I don't get into the situation of having an enemy at my tail often anymore though as I check the surrounding and don't engage on enemies that are flying in a group. Most times I die to tail gunners or because of several hits from several people over a bunch of minutes. With checking surroundings and knowing the plane's advantages there is a fair chance to not get too many enemies on the tail anyway I feel.
Reducing speed, while lowering flaps and pulling up a bit sometimes works well indeed, but when the enemy is faster and overshoots he usually can pull up turn mid air and dive down again without you doing anything as there is not enough speed left.
I remember doing this with the fat Catilina though wehre the enemies often sit directly behind you as there is no tail gunner that can shoot them there, often just 100-200 meters away. Engine stop and they either have to dive down or crash into you and the Catilina often does not take lethal damage of it
Furthermore in Historical battles evasive moves can be a lot easier as the flight models differ a lot more and you can use your plane's advantages better. Furthermore the fights happen in higher altitudes than in arcade and it's harder for the enemy to hit you which gives more time as well.
But usually I experience that when I am behind an enemy fighter, he either dies or a teammate helps him and he doesn't die. In the end most evasive maneuvers just buy time, due to the arrow showing you where the enemy is and the 360° view, you don't lose sight on an enemy very often and losing an enemy requires mistakes on your own part.
Getting completely rid of an enemy fighter works great in biplane games and with planes that have a high speed though. Often I just dive down, knowing I am slightly faster than the enemy plane and slowly get further and further away from him. When he keeps following either teammates come to help or the gap is big enough to take some risk and finish him on my own.
But everyone has his specific playstyle there. I usually wait a lot and only get involved in dogfights whithout enemy number advantage, concentrate on bombers often and pick my targets very carefully.