With respect to the Os and Nats followings, I think a psychological difference between PG and a chunk of Montgomery county vs NoVA is that you don't have to go by Nats Park or the Woodrow Wilson Bridge in order to go the park. Traffic matters, and if it is about the same pain in the butt to get to both stadiums, that helps make your family free agents. From Largo, Bouie, even probably Rockville north, it's just about as easy to drive to Camden Yards as it is to the Navy Yard. Don't forget it was Edward Bennett Williams who figured out that Camden Yards was a much better location to draw from DC than Memorial. EBW also opened the Os stores in Farragut Square. It's not just Angelos that targeted DC.
Supposedly EBW bought the O's with the intention of moving the team to DC. Baltimore with the big time assistance from the Maryland stadium authority made EBW an offer he couldn't refuse with Camden yards. He went for it because it was right at the end of 295 and as close to Washington as you could get and still in Baltimore. You're right, he then opened the O's store with the idea of making the O's Washington's team.
