Generally speaking any LPS coral can have the potential to harm non LPS corals and need their space. My frogspawn has extremely long tentacles that come out at night....5" ones. I have to be careful not to place any tthing that it can harm too close.
The tanks that have all the coral touching have them arranged by groups. You can have like corals, same grouping....SPS, LPS, and softies together. I have my softies touching, my LPS coral are grouped together, and my zoas are grouped with my mushrooms with no ill effects. Good Luck!!