This is a really good suggestion if it's possible for them to display retainer names in the Mogstation. Seems like it would fix the problem if they were just explicit about which would remain.
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Yep.
It's possible to move them in the list.
To make sure you never get this issue anymore, put all stuff from them in a chest (good luck with that) and then "delete" them (by selecting "dismiss their service" or something similiar while you talk to a rentainer vocate in any city that has one).
They are easy to level up anyways and in this way, you don't need to bother with them anymore :3
I don't see how that solves anything. Just figure out their order by resubscribing to retainers until you identify the current #2 and put it back in its proper order for future reference.
No need to permanently delete retainers unless you're adamant you're never going to use them again.
On the contrary, it's useful to keep them and make use of them as long-term storage for items you're not currently using but don't want to let go.
You mention selling stuff. To sell stuff consistently and not max space out on retainers on Balmung you need to be able to check prices multiple times. I am not invested in the game enough anymore to play the MB game. If they had something like we had in poetics before it got nerfed where get X item and just vendor it I would be a little happier.