Its clear to me that u guys never played dedicated xbowman. It is not that easy, for first u need great awareness of the surroundings, a lot of planing before u do anything and wise choice of cover. Yeah 100 dmg is huge, in fact it is in most cases one shot wepon BUT 6 heirlooms is not that easy to have AND for this 1 shot ability u get sloooooooow reload, dunno what u think but in 5 minutes round u fire like 10 bolts which is not only boring but not THAT effective inlcuding the miss chance. On the long distances u will always lose with archers what ususally forces u to go shotguning where u lose to throwers, and shotguning is only a oneshoot thing unless u want to go for cover after every shoot. Xbowing is not easy, Xbowing is not OP and sometimes is ass boring.
However the light xbow should take 2 slots.