I think this is a phenominal idea! I don't know much about coding really, but I mean, they've already got inventory in the game so you'd just need a way to put it on a looter, and then at the end of the match it clears it and gives gold (if that'd even be the easiest way of going about it).
This would also be an awesome solution to armor prices being way too high! And at first I thought it was bull**** that Khurgits would get horses to help loot, but now that I look at it, they have one of the highest armor prices in the game, maybe the highest if you include the better horses. But at the same time, like Synapsis said, it does kinda take away from being able to pick up enemy weapons. But, I suppose if looters have almost no armor, they're going to make juicy targets for archers/xbowmen and may die quickly and still leave alot of junk on the field to be used! Besides, you wont see a looter near a battle much except maybe way in the back, and if your side wins that few-man skirmish, you'll be able to pick what you want and leave the rest to the looter! Plus anything you may have to drop in exchange, he can pick up for cash!
It would add a whole new depth to the battlefield and a whole new tactic! Like, if most of your team sucks or is doing horrible, more people could go looter to ensure that the good players of their team have better equipment more readily available, giving them a better edge. In this way, if the looters can do their job efficiently, you can tip the odds to your favor or back to even if the other team has better players or whatever the case. Of course it doesn't screw the other team's skill levels either, since if they're good/use the right tactics, they'll be able to rack up kills on the looters with ease and sweep the battle and win quickly. So in that reguard, it still comes down to player skill for boths sides!
And I'm torn about the medic thing. On one hand it's awesome, on another hand it may hurt the atmosphere of fear in the game that helps make it what it is. More importantly though, you'd have to addd looter or medic, not both, otherwise you'd see 1/3rd of every team being non-combat likely.