Basically all Ackbar is usually doing is let you double arc with your side arc only - most rebel ships have pretty basic front guns, for 38 points which is a pretty big premium.
The outlier is the assault frigate, which can do it with gunnery teams - effectively double double arcing.
Imperials have a couple of potential responses -
- Obvious one - deny the gunnery teams multiple targets in the kill zone
- The kitted out ISD 2 is the queen of the battlefield at the moment, but you will need two clean assault frigate kills to get its points back. This suggests outplaying the rebels in positioning and manoeuvring. If it can go one on one it should win easily especially if Vader is in charge.
- multi ISD 1s with minimal upgrades - can attack from different directions to avoid the gunnery teams, and again, in a one on one fight will smash an AF. Probably need a good bid to secure first player.
- Good old engine tech demolisher, if it can get a good approach vector. If it gets caught out it will get one shot.
- A decent fighter complement is a big help. I recommend firesprays - they can go after weak shield arcs by themselves and are very dangerous to wounded ships
