Before you read this answer my advice is to read Dungeon Master’s Guide errata here https://media.wizards.com/2021/dnd/downloads/DMG-Errata.pdf Chapter 8
@KrisKoletar @JeremyECrawfordIf I’m standing right next to 4 Paladins, is anything stopping their auras of protection from stacking?
identical effects don’t stack
— Mike Mearls (@mikemearls) August 7, 2015
@mikemearls @KrisKoletar Identical spells don’t stack (PH, 205), but nothing stops the auras from stacking. Could always house rule it.
— Jeremy Crawford (@JeremyECrawford) August 7, 2015