Woodies are boned on the artillery front and our cav, monsters and spellcasters would be easily overwhelmed by him. Fortunately, 30-odd Deepwood Scouts and a couple of Glade Rider units, all with poison arrows, would probably make short work of him. Hell, Sisters of the Thorn might actually be decent against him with their poisoned, AP javelins, poisoned attacks and ++4.
So yeah, poison spam could be pretty good against him!