If your polyps came from comparable lighting, you could place them anywhere. I always start low with any new arrival if I don't QT them first. I place them on the substrate to allow them to acclimate ,alone and away from any other corals until I can be sure they are ok. After that, it's trial an error. I would make one or two upward moves and then leave them there. If you know where they came from in the wild, that would instantly help with placement. Shallow water collected polyps you can place higher, deeper water collected polyps I'd place lower. Persistent moving of zoas and palys will only delay/stunt their growth.
BTW, current is a must with any new addition just in case they are stressed and start to expel.