I used to field them in groups of 10, but then I was sick of using my scroll T1 by silly things like a boosted Shems spell.
They're like HE sisters (Though Sisters can probably pick off a unit of 5 hexes no prob)... expensive magic missle magnets... Heck, even Flame Cage would lift Hexes if they moved.
Hex weaknesses:
Lores: Fire, Metal (Enchanted blades spell WWRRREEECKS them), Light, Death (I1), Shadow, Big Wagg (Stomp and Fists of Gork give magic attacks to the +3), and ANY other lore that has at least ONE magic missile.
OK: Firebellies, Dragonhide Banner Breath Weapon
HE: Sisters, Reaver bow, Loremaster, 2d6 S4 bound Spell (3)
VC: Gaze, Blenders, static res from zombies
DoC: Hexes are borderling useless
WoC: Ensorcelled weapons, Daemonic attacks, Hell Cannon magical template, heros, DPs, most Daemonic Lores, ENSORCELLED WEAPONS
Lizzies: See Lores above (If yoiu run into a Party Slann on Light... don't even bother deploying them)
Empire: See Lores above, light council
Dwarfs: Runes = Magic Artillery
Chaos Dwarfs: Hellbound
DE: I see alot of xbow units with enchanted blades, lifetaker
Skaven: Warp Spikes, WLC, Vermin tide (I was on the receiving end of this before... not fun), Plague, Gutter slings etc etc etc
Now I field them in units of zero :slapface:
But when I did field them, they were 10 strong with a champ, yiedling 310 VPs to my opponent.
In uncomped settings I supposse they have a place though with, say, 2 TGs soaking up damage as well... but that's gettign silly lol