Crop Rotation and Unspeakable Offensive

'has a chance'

'can drop'

yeah but what's the damn rate on these? 5%? 20%? How am I supposed to decide whether they're worth taking without knowing the chance?

By testing them. You should always take Unspeakable Offensive anyway because it makes Harbingers not excruciatingly slow. Crop Rotation is very easy to test, it will take you 1 spreadsheet, 2 maps and 5 minutes to check.

I agree it's annoying that it doesn't say.