[quote=@NecroKnight]

Hmm. I might say this would leave your factions too powerful.
[/quote]


I guarantee it won't be as buddy-buddy as that. They certainly have common ground and reason to pursue some sort of alignment with each other(I mean, they're pretty much the only the people they can really talk to right now where they don't have to worry about getting put in front of a firing squad for crimes against humanity), but The Institute is under no illusion about who these people are and what would likely be happening if they'd met under different circumstances.

I'm imaging for instance what might have happened if The Enclave in Fallout 3 had sent the same ultimatum they gave Vault 101 to The Institute. My guess is that The Directorate's response would have been something along the lines of "Fuck off" and then prepped the Coursers. 

Edit: Updated by sheet as well to match [@Leos Klien]