When you ask Arcade to join you when ED-E is in your party already, he will say that ED-E looks suspicious and that there are worse things in the world than destroying it with a Pulse Grenade. However, ED-E is Enclave technology and the guy who created it told it to go to Navarro, Arcade's original home. Shouldn't Arcade have recognised ED-E as Enclave tech and done something about it? Even if he didn't, someone like Judah Kreger, a former officer, should have recognised ED-E and interacted with it. Also, there should have been an in-game option to tell ED-E that Navarro was no more. There was a big missed opportunity to have the Remnants and NCR senior officers like COL Moore and Chief Hanlon interact with ED-E in-depth.