Just to put things in perspective, in the most recent transfer TNA received 4,837,951 individual sets of records from around a dozen Army Record offices, all of which used slight variations on how they indexed and filed the information. All of these files were moved in large containers, only some of which have so far been opened and fully processed. As mentioned in an earlier comment the TNA staff have go through every set of documents to re-index it, digitize the contents and do conservation as required on the originals, and then transfer the information to the TNA Discovery portal. Any requests for documents by members of the public have to be fitted in around this work. I believe the team working on all this is less than a dozen in number, although that may just be the processing and indexing staff.