Thank you for the review! I'm a hobbyist creative writer so I tend to design from a narrative perspective and then make mechanics to match that narrative.
The ability berry is to protect the shepherds from being locked up in coffin makers actually! I had a test game where all of my shepherds got eaten by my Shroomlings at the start of my turn and I couldn't get them back out to score and win because they had coffin makers. :( Not sure if that is worthy of an ability berry, but it seemed like a bad interaction that a single crafted card could keep the shepherds from scoring.
P.S. I love all of your artwork.