There is a danger of making past/peace/anarchy even stronger if they are color specific.
I do like the idea of buffing blue starter somehow though.
The balancing act is the opportunity cost of building a certain addon. If I build a tower, its that much ahrder to build a heroes hall.
Blue super tower seems kinda boring. Better boost: Blue Lookout Post. When you build this, get a 1/1 soldier token with sparkshot + Tower, cost 3. slightly more interesting.