I would rate the stalkers at XXXX. In the last week I have played 8 games against tomb kings and my opponent took them all but one time. Even though math says stalkers shouldn't do that great, they do great. Even though our monsters are protected by skinks, they die easily. The stalkers seem to work just like sallies, they either misfire or hit just right (and by just right I mean 20-30 hits). And with 20-30 hits it's easy to roll 5 sixes. They are also good at sniping solo slanns. The shooting is magic attacks and they are quite good at hitting just right. The only ways I have found of dealing with them is magic and a unit of skirmishers.