I was looking for this too...Anyone knows how to?
EDIT: I found this:
sm_cvar versus_tank_chance_intro 1
sm_cvar versus_tank_chance_finale 1
sm_cvar versus_tank_chance 1
sm_cvar versus_witch_chance_intro 1
sm_cvar versus_witch_chance_finale 1
sm_cvar versus_witch_chance 1
In this topic:
http://forums.alliedmods.net/showthr...ighlight=witch