and really the melee does nto get blown wide open at the level 17 - 20 range like you think. while the other classes do get the dual wield and double attack skills at them levels, there skill levels remain low enough that a 25 percent double attack rate is not that uncommen up to around 32 or so (lower if they do spend the tiem to keep it up and slow down on leveling now adays). and even that we hhave near enough to warrior skill caps on our wep skills on up to level 50 that our damage is only around 1/2 half that of warriors useing 2handers and 1/4 that of warriors using 1handers. Now adding half a warrior to any dot damage your doing is a decent adition. post 50 is when there skill caps go up and ours dont, plues I think warriors start being able to trip, but we are still some what on the same ratio tell 52 or 53 I think and still not that much degraded to level 60. post 60 and post AA more importantly we start dropping off the radar, but still melee while tanking for your pet you will still do as much damage over the course of the fight as 2 or 3 of your dots ..... which means you made the fight shorter by about 1 to 2 refreashes depedning on the types of dots you have (LDoN).
And if you can get ahold of a cleave 3 aug It helps as well

. It feels like while swing a 2hander I am getting about a crit every 10 swings or so (about a 9 to 10 percent crit rate, or about the rate of a unAAed warrior). not game breaking but something. I have a feeling that the augs that add melee crit rate on a person with none instead of addign 120 percent of nothing (cleave 3) add just about 12 percent (unable to test cleave 4 and 5's becouse there are none shaman useable). this may mean that if or when you get the DoN 3 percent crit rate AA that any melee crit rate you have would get nerfed down to about 6 to 7 percent.