You might get some good analogy by reading up on the history of flight and air combat during World War I, and how it came to effect the battlefield. I think there are some parallels with the early days of combat flight and the world you're describing.
Until 1914, the aerial presence in warfare (and life in general), was pretty much limited to observation balloons that were static, and principally used to sight for artillery (balloon use continued throughout the war).
At the start of WWI, aircraft were also pretty much limited to an observational role, and enemy pilots would sometimes wave at each other in mid flight since they couldn't really do anything to stop the other pilot from taking pictures (some carried sidearms, or a second passenger with a firearm or machine gun of some kind, but the chance of an accurate shot was miniscule). The pilots also tried to fly higher than ground based forces could accurately shoot, when possible.
Then, one day in (I think) early 1915, a German plane flew straight at a French aircraft and began firing through its propeller! The Germans had mounted steel wedges on the wooden (!) propeller that deflected the machine gun bullets that would otherwise smash the propeller (granted, eventually the kinetic shock shook the propeller to bits, so it was of limited use). Shortly thereafter, a chain linked to the propeller's rotation and synched with the firing mechanism on the machine gun was developed, and planes could dogfight (more effectively). Aircraft also began to carry bombs (though nowhere near the scale of payload seen in World War II and beyond), often dropped by hand by a pilot or observer.
Technological developments followed in WWI flight in a way that might influence how flight affects the world you're describing. It might take a while to develop effective counters, and the fliers may begin to figure out things like bundles of alchemist fire flasks dropped (bombs), or archers on wingback (gunners), etc. Though air power never was a completely deciding factor in the outcome of WWI (as Wulf Ratbane observed, you have to have troops on the ground), it was recognized as an arena that would become vital in future conflict.
Hope that helps.
Warrior Poet