For many years now people have wanted a change regarding planes being "OP". What makes planes the strongest unit is that they are the only unit that can attack other unit archetypes (ground/navy). Not only are they able to attack other units, if they have no air units standing against them, they kill units without suffering any losses. To address this, either planes need to only be able to attack planes, unit wise, or ground and navy need to be allowed to attack other units archetypes as well.