[Arralen]

No, you can't mod random events, they're hardcoded. This is not changed in Dom3,btw. Therefore, unless there's some bug in the modding code, loading whatever mod should not affect the occurence of the "witch event" only. You may have more or more severe events in general, though. Btw., I don't think the "witch event" is considered severe.

Furthermore, having your entire army cursed is definitly not the work of a bunch of witches. If you get that event, you'll told how many units where cursed. If there's no number given, it is "0".

You know what? Next time you'll get such a "mass curse" event, zip up the savegame and attach it to a post here in the forum, and I'll have a look at it.
Better yet, zip up every turns files and keep them, then attach both the events turn and the preceding one (zipped again in one file, you can only attack 1 file per post here!) to your post.

Anyhow, being cursed doesn't make a great difference to the standard human infantry unit - it dies after 1 or 2 hits at best anyway. Number of additional afflicted units which survive the battle is normally negligible - you'll have some after every battle, cursed units or not. And some afflictions don't make that much of a difference to those units anyway (Lost an eye, Battle fright, Weakened etc.). Therefore, no big deal.

This is somewhat different for high-hitpoint units, like Jotuns or Centaurs, which are considerably more expensive, and o.c. commanders which should do melee fighting (speak: SuperCombatants). Being cursed is negligible for a mage or a troop commander set to "stay behind troops".