I think it is more a matter of Petro not faithfully representing the capabilities of ships. It is unfortunate that it takes the mod community to make units operate as they should have out of the box.
1. Capital ships should be excellent against corvettes but piss poor against fighters/bombers unless they have laser cannons. Currently their shots seem to miss corvettes way to often for my liking.
2. Corvettes should be good against fighters because of fast tracking laser cannons, and excellent against bombers due to their slower speed compared to fighters. Corvettes tear through fighters too quickly right now but are about right versus bombers.
3. Fighters should be good against corvettes because of their speed but expect losses. They should be decent against capital ships but lacking the punch of bombers.
4. Bombers are horrible against corvettes but excellent against capital ships. They are fine as is.