Streams should only have one owner, but should be able to have up to four co-owners. Co-owners can do most things the owner can do, not including deleting the stream or changing the owner's mod status. When the owner deletes their account, any of the co-owners can take the spot of the former owner.
Also, in the mod list under stream settings, the owner should be listed first, followed by the co-owners listed alphabetically. After the co-owners are all the mods listed by name, and finally all the pending mods.