Expanding the radars, lowering dar limits, all that won't work.
All that does is make it so that more people are required to take a base. Under the old town design, it required less people to take a base. Less skill to approach in a straight line to blow up the entire town with 3 bombers, less fighters to buzz the town, LCA used to take bases quickly, and now it takes more people to kill a town.
Every time you up the challenge, you make the hordes (military supremacy) larger.
As much as I hate the white flag, it did lessen the 'horde' necessary to ensure every single building was killed. At 100% town down it was very very difficult to tell, bases did not capture many times due to the 1 building missed, more fighters were required to cap/strafe/shoot down fighters.