How exactly does this thing work? It says it allows ganging up at range, but it's far from clear what this means. Is this just a straight +20 to hit for everything, with the players being considered to outnumber every individual enemy 4-1? If so do they have to have a ranged weapon equipped? Does it have to be able to shoot to the targeted enemy? Do they have to attack the same target to count as ganging up? If so does the first person who fires get the bonus?
Really seems to me like this needed a little clarification in the rules, extrapolating the melee ganging up rules to range is far from an easy matter.