At the moment archers are undervalued in score and melee overvalued(thanks to proximity bonus). Score should reward players for what they contribute to their team effort, so I don't see why any random archer should be worth more than say, a melee guy with a 15:1 K:D for the map. Score needs changed, but not like this. The reason ranged doesn't yield as much score, is because score takes your raw damage, not final damage and raw damage is figured just before armor is brought in.
Edit: Also, this won't decrease ranged, this might convince ranged to shoot at each other more often, but I highly doubt it. Most ranged don't shoot at cav and yet cav provides a lot of easy points.