The battle continued on as both sides fired shots at one another generating loud booms and waves that devastated the surroundings. But after being bombarded continuously for about half an hour, the barrier protecting the city could no longer withstand the attacks especially after the three Commanders coordinated their attacks with the cannons eventually taking down the city's barrier.
But as they intended to proceed to bombarding the city directly, the tier 4 Emperors in the city flew out as they faced their opponents a few miles above the city ensuring the city wasn't affected by the shockwaves of their battle. Even though battles between tier 4 Emperors are significantly less destructive than tier 5 Saints, ruining the topography of a city still wasn't that difficult. And as the aim of the attacking forces was to take over the city, they didn't want to leave the city in tatters too so they had no problem with fighting at high altitude.