I agree. Air should be no match for naval units. It currently ruins the naval play with air beating naval. It's all about units not being too versatile. Naval should be slow and tanky (high health and firepower), with air being fast and fragile. There should however be anti-naval land units/structures that can be built along the coastline to protect against naval bombardment (if you choose not to build naval units yourself to counter, there should be land alternative for defense).