You can - there's a number of tutorials and examples on that. But there's different ways to do it. Since ARC was designed to control one robot per instance of the software, that's the easiest way. Can you elaborate on what you'd like to do?

Actually, it's kind of neat but this robot was controlled with one computer

Robot scoot'n boogie was truly cute and funny and quite amazing how many robots can be controlled under one software system love it.xD