My sage is constantly over DPSing all marauders/sentinel in WZ (most time doubling them unless some very good ones). Yes, sent/mara can put 5k numers with 1 strike and sage/sorc can´t but also they have to move behind all toons to get melee range when we are in strategic spots just nuking everyone in 30m range.
Just an example, in The Pit, sage/sorc in high spots a marauder jums on them, then just push him down and DOT him while he is running all the way back to your spot , when finally he reach to you again another push and he is again down...then he can jump again to you but then it should be too late for him
Sages/sorc have a lot of advantages comparing with marauders/sent, use them!
BTW, here is a video showing how to duel vs a marauder. Enjoy!