Believe it or not dueling can teach a person quite a bit about dogfighting. Merges, energy management, throttle control, gunnery, learning how to fight in a stalled situation ...so on and so forth. I for one find dueling a better learning tool than asking a trainer for help. There are so many good cartoon sticks out there and they all seem to have a different bag of tricks, so IMO someone can learn more quicker.
If you want to get better at dogfighting this is how to go about it. If that's not your goal that's fine too.
DA never taught me to fight, its a great tool to learn ACM however I know some awesome dogfighters who can't live 15 minutes in an FSO. The Main arena helps with this, jump into a furball with a less then decent aircraft, learn SA and survival tactics.
When you combine the MA, Scenarios and DA - you become a much better pilot then simply the DA.
Once you learn to balance the three out, you become a much better pilot IMO. Honestly if you can break even in the DA, you are doing just fine.