There is no automatic way to sync a Case File across multiple iPad devices between different users. However, using a shared folder in iCloud Drive, a Case File could be accessed by multiple people who have access to the shared folder. One user could access the Case File from their iPad, and another user could access the same Case File from their Mac. However, if the Case File is edited on multiple devices at the same time, or on a second device before the first is brought back online, you may lose some changes.