Wasn't sure what to think of this thread at first, but the comment about the Random Happenings being a deck of cards really stuck with me. I think I'm going to try and incorporate that into my next campaign (using a simplified variant of the Mordheimer's Campaing Aid).
Beginning of campaign turn, draw a card. You get "Sudden Downpour" which might read something like:
All games being played this turn are affected by a spontaneous heavy rain storm. All warbands will have trouble with spotting, making
ranged shots, and performing physical feats (climbing, jumping, leaping, etc.). ..
I've never been a huge fan of the Random Happenings table mainly because it's an extra roll people will forget about half the time (especially when someone is having to roll animosity). However, making it a random card draw every campaign turn that can affect some or all battles has a certain appeal to me!