WE are my second army, after VC. I became bored of them very quickly. despite having a giant bag of fun tricks, there are only two ways to win with them- the first, most hated and way i refuse to play is to put all fast cav on the table and basically play by yourself until time runs out and youve won a marginal victory. The second is to wither your opponent, turning every bow into a guided missile launcher that will blow your opponent off the table.
WE are naturally strong against any army with a lot of T3 but without wither, an entire army can fire at one monster and do next to nothing.
As for waystalkers, they are a gimmick. With bow of loren they get two (magical) sniping attacks that ignore armor, with the option for 3 attacks which wont ignore armor. Like all S3 shooting, it wont ever amount to much, but with scouts and 30" range, you cannot avoid them. With your best efforts, you can probably get him down to 4+ to hit, which is scary for your necros. A vamp lord is wounded on a 6 with a 4+ ward and the ability to heal or be healed quite easily, so you should not worry about that.
Wild riders are the fast cav you cant ignore. They are not expensive. It dosent matter where they hit you. They are a kamikaze jet that will sink you. A 5 man group that hits you can easily blow out 20 wounds before you get anything to say about it, that might be 40 with crumble, though you just have to kill 5 nearly naked T3 units to not have to worry about it. Thats why you don't want to get hit in the flank. Hit these guys with gaze asap.
Any magic attack that causes wounds will melt their points fast. Glade guard are very expensive yet one naked T3 wound apice.
WE lose when engaged so VDM in their face. Their ASF wont save them. But any WE player that that dosent love pain is playing with khaine rules and threw in at least a couple ballistas, probably some nasty HE anvils or DE hammers so its a whole new world now