In the arena, if you take fighters with your fleet, and the ships get destroyed, but not the fighters, the fighter amount remains unaffected. What do I mean? For instance, I just fought 41 transports. 41 transports should be able to carry 820 fighter max. But this fleet had 1256 fighters, 50% more than max. How did that happen, you ask? Quite simple. Stick in 200 transports with 4000 fighters. Keep challenging people, but do not launch fighters. Over time, you lose your ships, but your fighters remain unaffected. In this manner, you could weigh in at fleet strength 2 (1 transport left), but have 4k fighters with you. These players need only survive the first round, then they can overwhelm their opponents, even if the opponent is far more powerful.
You need to make it such that excess fighters are removed from fleets after a battle has finished.
This coupled with the targeting issues, energy issues, and init issues makes arena battles extremely hard. And I see these issues are not resolved on the test server either.