My tactic is to avoid dedicated AA designs, but to make my whole fleet have distributed AA capabilities. In other words, my cruisers have 1 - 2 cruiser pulse lasers, or if they’re tribe I use 1 autocannon instead, and I have a rear line of frigates. This rear line consists of frigates with 1 AA/pulse weapon, 1 tractor beam, 1 point defense, and the rest being frigate smallbeam lasers; tracking is no issue when fighters get caught by the tractor beams. Rocket fighter swarms of 16 - 48 fighters have been staved off by this.
Do note that I’ve not tested it against challenges yet. (Very new strategy for me, this one.)