Dragons usually wont intervene on mortal issues usually so dont expect them to do much unless their species got threatened by the Empire. Ishgard anti air weaponry is mid range at best since dragons ranged atack is limited in range, meanwhile Garlean ships can bombard from afar carpet bombing style. Ala Migho was on its prime as strong as the three main cities combined, but King Theodric civil war weakened its power making an easy pick for Gaius Van Baelsar. Dalmasca is more of a conquered yet not pacified region with guerrillas roaming around, but they werent a serious threat until they joined forces with Orthard and even so their victories were bloody

The most worrysome issue for Garlean Empire are the primals due to their wild card nature and lack of counters against their tempering