While bombers are the best counter to artillery that doesn't mean there isn't an issue with the relative cost of artillery and bombers. If 2 bombers that have gotten through AA is enough to kill an artillery piece then that is obviously different to if it takes 10. There is also the balance issue of given equal resources how many bombers can you build for one artillery. Of course discussing the numbers backed up by real game examples is the best way forward but that is a relatively large amount of work. On another note a T1 bomber should be able to kill a T1 metal extractor on one pass, to make the strategy of early air raiding viable.
I really like that concept of an imperfect artillery defense, something with a success chance of 50% for shells, and 60% for missiles. I basically posted this, because at the moment you can have a slowly expanding base tactic that is "aggressive turtling".
The game should hopefully be balanced tho so that in some cases a slowly expanding turtler can be outproduced by a rapidly expanding swarmer. So power of the turrets is outweighed by control over a larger area. Then with sufficiently diverse map types and sizes you pick your strategy, 'turtle and turret creep' or 'expand and swarm' based on the map. That way the game has some strategic diversity and depth.
That's currently the case, a slow expanding turtler has no chance of winning against a fast expander. I'll just have so many more tanks then you do so you can't possible attack and defeat me. The current issue is that attacking a well entrenched turtler is pretty hard, as ground units get quickly obliterated. To solve this, you don't need arty counter though, just make the t2 tank more specialised. Instead of it being just a better version of the ant, give it even more hp and reduce its firing speed considerably. So that it can reach static defenses and also destroy those defenses while being still swarmable by other units. (When we get formations and thus spacing out of units instead of unit blobs that area easily killed by aoe this issue gets solved anyway.)
