What does FO1 have? An organized Super Mutant presence, and Vault City. That's about it, aside from some traders, raiders, and the odd settlement.
Did you even play FO1?
Vault City (8) was not in FO1 for starters.
I'd hardly call Junktown, Adytum, or the Hub "The odd Settlement". These cities had a defense force and population on par, if not bigger, than Megaton's or Rivet City. The Caravaners were stronger and much more developed than the "One Man Bands" in FO3. Heck, FO1 even had a an organisation with a working munitions/weapons factory (the gun runners).
Project Purity was a single project by a few Scientists - Do you really want to compare this to the main BOS Stronghold?