Actually gemmers can't keep searching for battles. They have to take the first one that they come across.
due to the massive time they spend online and the fact most are attacked at the exact instant they log off it's they click once in the search button and they spend hours looking at the "searching" screen before they actually find someone to attack. And they have well protected and well upgraded air defenses, so they won't use this strategy.
And I like the idea. It's sure an interesting twist it would be add new strategies. We lack a splash air defense except wizards, that has very little range. If you turned the mortar into air, you'd face a new problem minions attack. Also the air defense has the highest DPS of all defensive structures, so you'd have to think about it. And if the X-Bow was targeted to ground only it would target the air only, so it wouldn't attack ground troops.
This idea would sure be a nice addition to the game
