This actually seems relatively straightforward to me, but I could see the confusion and I want to verify before I pull it out of my bag of tricks. Demolisher can perform one of its attacks after it performs a move. When attacking squadrons, you get to make a roll against every squadron within rang and the arc you are shooting from. That counts as only a single attack.

So, if I have Demolisher, it seems to me that I can move first and then attack every squadron within an arc? Thinking about a Demolisher with Ruthless Strategists to fly around with some TIE Bombers...

Yes.

Indeed. It is "relatively" powerful to do against squadrons, with a Gladiator-II and other appropriate upgrades. Of course, at which point, you either need to load it up with other upgrades to make it a compromise of Anti-Ship or Anti-Squadron, or try to keep it cheap, and get neither of the compromise to its full effectiveness...

The conundrums of Ship Building...

Whenever I try to make an Imperial squadron heavy list, I have a really hard time putting in a lot of TIE Fighters. Enough of them working together can put a fair bit of damage onto a ship, but 3 hull makes them so... killable. Anyway, I always want to put as many Bombers as I can onto the table. To that end, I like the idea of Ruthless Strategists on a Glad II. Demolisher just makes it a lot easier to catch all the opposition and make the shot count. Plus, even with no other upgrades, a naked Demolisher isn't a bad thing to have when you need to punch a ship.