I had created some designs like that, which I call 'Bombers' a few weeks ago, before I had the box, but then I scrapped them, because I thought attacking soft targets meant declaring war and having it expand into a true war.
Yes, an attack is an attack. You use these to raid during a war. They give up firepower and defenses for range, speed, and early warning.
The designs were Medium hulls, with lots & lots of engines, some life support, a survey module(thats all you need when you've got Eyes of the Universe), and the rest is either weaponry, or one weapon and lots of defenses.
Its a waste to use a medium hull for this. The whole point is to
avoid shooters and kill valuable defenseless stuff. For that, you can cram more speed, range, and sensors...and one shooter item...into a cargo hull. Oh, and at high difficulty you can't always count on being the first with any particular Galactic Achievement - the AI knows their value also.
The Survey module is also a bit of a waste, unless you haven't been able to afford the time to go to SensIV, and there is too great a premium on space for an extra Sensor. By the time you are using these ships, the anomalies are generally all gone, and a Survey mod is very expensive.
Too bad Asteroid Mining Bases are the only things that can't be armed. Freighters, Mining Starbases, Economic and Influence Starbases, Transports, Constructors, Space Miners and Spore Ships can all be armed.
But they usually aren't until late in the game. By then continuing miniaturization should allow you to protect your raider a bit while maintaining its range and speed. Actually the AI rarely arms constructors, miners, and influence SBs even late in the game. I've never seen weapons on a spore, but I happen to have encountered very few. They are escorted part of the time, though.
drrider