Okay, for the sake of argument, lets say that a map has, oh, 30 enemies on it. Now, being the enterprising scavenger you are, you go out of your way to hit as many as you can, in order to get loot for your team. Let's say for the sake of argument that you managed to hit a third of them, and to further uncomplicate matters, they were the cheapo classes.
You just made your group 1000 coins. Which is a farily conservative estimate. If we dropped the amount down to 50/100 per hit, depending on class, you'd still be making enough to buy a couple weapons/one special weapon darn near every map.
Scavengers too useful to group finances, plz nerf.
@ Fighters need something else, but I'm not sure what. Making them sneaky tree ninjas is dumb, they wander around hitting people with axes for Critz sake. Maybe an inversion of the Mercenary skill? Except we're planning to change that.
The challenge thing: An idea I had for Fencer's (Though maybe it could work for Fighters if we decide Fencers should have something different), was that they could designate an enemy to challenge on the map. The fencer would gain a few bonuses against them, like increased Hit and Damage, and the enemy would do their best to attack the Fencer, and only the fencer so long as they had the option. The challenge is removed either when the target is dead, or if the Fencer moves in any way that increases distance between himself and the challenged unit. It gives the Fencer a skill that is useful on any map, and gives him a little battlefield control. As a one shot ability however, it may be limited. On the other hand, it'd be darn useful.