The main problem with scoundrel is that most of the skills are not worth using for damage. This leaves you in a position where standard basic attacks in the backstab position are pretty much always the best option. Even most of the utility options are outdone by low level magic spells you could pick up for a few skill points. Even if their raw damage is high, having basic attacks be your best option is just not fun play, at least to me.
At least marksman offers a few decent attacks and a couple decent utility skills that are very much worth having on your bar and using. Then the variety in arrows gives another addition to the combat for them. While they may not have the same raw damage as 10 backstabs in a row, it is more entertaining and fun to play.
Man at Arms really only has a few good damage skills and a few good utility skills as well. The main reason it gets a lot of attention is 2-hand damage output. If it was not so high compared to everything else then people would complain just the same. The only thing people talk about with man-at-arms is the uber damage they do. It doesnt offer anything else.
Personally I think scoundrel needs a complete review of the skills, with at least a few of them made into something better than backstab spam.
Then they need to make physical attack skills have reduced cooldowns with increased physical attributes, the same as spells get with intelligence.
if it throws the damage out of whack, they could probably amp up spell damage in some regard, because honestly spell damage is pretty low. its just all utility.
right now the best set up is to have your spellcasters act as buff-bots and controllers and have the physical guys basic attack for the win.
it could be so much more.