Man you are on a roll! Those are some nice bunches of seng you have dug! Also, that last one is a nice chunky one that from it's appearance and what you stated, it was apparently a merger of two plants growing right side-by-side. I have seen this happen quite often over the years! If you are growing or watching over some plants year after year and see two plants growing that close, you might want to dig around them and separate one of the plants for replant futher away. This gives both plants an equal chance to grow to their own potential!