I used to enjoy doing CZ in my CM4.
But then FD increased ship health in CZ to ridiculous levels due to how easy people in big ships could take them down making CZ combat in a small ship very frustrating. You can literally spend 10 or more minutes blasting away and still not take down the shields on an enemy.
Combat was at its best before all the HP inflating modules for hull and shield and engineering.
And I agree that was a pretty stupid way to balance things. Typical solution for developers, sadly.
People in fully engineered big ships SHOULD feel overpowered and completely lay waste to CZ's and such. Instead they inflated NPC health and abilities so big ships now just feel "good enough", and guys like you in your CM4 take it in the pants. Did they even consider how that change would impact players like you? Doesn't seem like they did...