Ladyt

We brought a 57ft sail away but as we were uncertain of our layout did not have the mushroom vents fitted. Are there any rules in regards to positioning? I noticed for BSS there are rules for being next to a flue but can not find anything about the positioning of the other vents. We have 4 in total. Is it just personal preference? I notice on pictures of other boats they are not always in a long line or space out evenly. Any help or suggestions would be greatly appreciated. Many thanks