Running the same project from different instances of unreal wont work because each instance will be updating the files in the project all the time and the others instances wont update the new modified files without source control. for example for modify your gamemode in one computer and save all, the other computer with the same project wont notice and still using the old one and so on…each time someone saves a file it will be update in the folders but the other instances wont notice.
Why don’t use Multi-user editing instead? No need perforce or source control platforms
and set it up and get used to it is not that hard
https://www.youtube.com/results?search_query=ue4+multi+user&sp=EgIIBQ%3D%3D