Dueling in the arena as a ranged Scout is like trying to climb a tree as a fish.
Ranged Scout needs to abuse his range to be able to defeat most classes and pet classes are always annoying. In the arena you won't be able to do this. Try to have the player and the pet tranquilled at all times so it does not reach you. Also always keep Incendiary Arrowx3 on the player. Caltrops also helps a lot. Everything else is just hoping for Double Shot to refresh
But wait it gets better! Warden pets bug sometimes being untargetable
But Warriors/Pallies/Bards/Melee Scouts basically have no chance in and ideal environment for you (1vs1, endless flat plane)
Ranged Scout requires a lot of awareness in mass PvP or you will be just destroyed as soon as someone gets close.
My advice: Wait until the patch hits, then maybe we get a WoD or even FoD.
Showing us your build would also help: http://www.allodsbase.com/calc#