Simple render farm for Macs

Hi, apologies if this isn't the right place for this question. I have some Macs located near each other in an office. I want to connect them together via ethernet to share files quickly and form a small render farm. I also want the Macs to connect to the internet via a WiFi router. But the file sharing must not take place over WiFi. What is the simplest way to achieve this? Thank you!