TfL management needs to acknowledge that it's in a battle it can't win simply because the unions, especially RMT, are in a position of strength and have a mindset to continually flex their political muscle. Of course they need to modernise and get rid of redundant jobs like issuing tickets when no one wants to buy tickets any more (except the dwindling 3% who will have dwindled to virtually zero in a couple of years, and a few tourists who will still have ticket offices at main stations. Oh, and anyone else who will be able to approach roving staff armed with ticket machines at any station).
Which means getting rid of a few highly paid jobs that are no longer needed, in a situation where to do so would precipitate action by a selfish, hypocritical clique causing massive inconvenience to other workers, London's economy and reputation, and visitors.
So rather than plan any job shifts, what TfL needs to do is simply phase out the ticket offices as and when those staff leave or move of their own accord. Messy, but practical in the face of resolute intransigence.