I can see where you are coming from with this idea, but I personally feel that the system as it is is ok. It should be really difficult to get through to bomb such a heavily dfended carrier as an Emperor. So just because 8 squadrons has difficulty, it doesn't mean the system is broken, merely that you need to chuck more wings of bombers at the ship. Plus, if we do what you say, much weaker ships with only 1-3 turrets will be almost helpless against bombers.
The game is not meant to be all about ordanance, so we shouldn't make it more effective.
The problem with the current system is that bombers should be the bane of unsupported ships especially cruisers and battle ships. Ships that have support should be almost immune from bombers. Escorts from a Chaos point of view are currently a complete waste of points and are only really seen as gun ships in the rest of the fleets. Cruisers would be at 3 or 4 turrets depending on the ship, with escorts other cap ships and the cap you could get them higher than the current 2-3 suppression you see at the moment versus bomber heavy fleets.
Also note there would not be any ships with 1 turret.
2 (1 in old) turrets on average would be equal to their current mark
3 (2 in old) and higher would be weaker.
to make up for individual weakness against bombers all ships have slightly higher survivability against torpedoes.
However supported cruisers have advantages. Cruiser with one ship in base contact would get suppression equal to the current system on average. Any more ships in contact would be at a higher average than the current system.
This is not about making ordinance stronger. It is actually making it weaker over the whole whilst allowing players to maximize there fleet against it.
The only issue I have is Eldar ordinance. How do we fix them?