Hi there!
NetApp FAS/AFF aggregates don't rely on drive position at all - when turned off, you can pull drives out and move them around, or re-cable shelves entirely.
If your organisation can't take the downtime to do so, there are options for moving shelves around while the system is still running, but I'd recommend you engage NetApp or partner PS to perform this activity.
In short you change the SAS stacks from double ended, to single ended, with each on one controller, then do a takeover and recable the one that was only connected to the down controller (single ended), then giveback, takeover the other one and do that one, then giveback, then re-transition to double ended SAS stacks. It does introduce risk, so make sure you do it in a pre-determined change period.
Hope this helps!