All these leaks are from the same guy who’s already in custody. All of it’s available on SIPRNET so its completely within the power of one person to download it all and leak it. Classified systems really shouldn’t have burners and USB drives.
I respectfully call BS on your assertion as to who is to blame. No place, no where does a PFC have access to State Department information unless someone gave it to him. Just because you have access to military classified documents does not give any access at all to State Department classified files.
The chain of custody rules also address in a big way with the very basic “Need to Know” rules for the dissemination of any of the documents. He would need very unusual permission to have access to information other than was necessary to his immediate job and that access would be very documented.