[Kobal2]

Swarm is so-so - the bugs don't have enough skill to pop 20+ defense while Glamoured thugs certainly can pop one or two squares worth of bugs per turn.

Poison cloud I can vouch pops it, but it's usually not enough to kill them (and unless you're using undead, is very annoying to use with troops).

Breath of the Dragon has real short range for a nuke, even more so for a DoT.

If you have Growth, then vine arrows (both the spell and the item) and Entanglement are excellent options, since neither Vans nor their Huskarl cohorts have particularly notable strength. Pop glamour and nix their high def in one go.

All in all though, a gaggle of shortbows is generally all you really need to solve the Glamour problem itself. Once that's done, any anti-thug tactics work.