I’d probably say the biggest change to old game play is that NPCs now have a happiness system. This is determined by biome and other NPCs around them. So you do have to space them a bit apart due to over crowding, it’s not required but if they’re unhappy prices go up. Thankfully you can set up Pylons to teleport around the NPC villages you build for every biome except for Corruption/Crimson. I hope this helps