Alternate title: I love the Artemis
Here is a Junker build that I've been using lately to astounding success:
Bottom Guns: Gatlings - put a gunner down here for dps.
Front Guns and Top Guns: Artemis Rocket Launchers - your engineers had better be good shots.
There are three reasons I think this works so well.
1) It combines explosive and piercing damage. Its not as good a killer as Gat/Flak, but it is good. When all is going well, this build can easily maintain 3 guns firing on the enemy - the 2 Artemis' explosive power gets the job done.
2) Everyone has fun crewing it. This might sound stupid, but good morale keeps everyone sharp. Everyone will be firing almost all the time.
3) With Pyramidion Gat/Flak so present in the meta, the Artemis is excellent. Let me explain why:
Pyra Gat/Flak is a quick killer that inexperienced crews and pilots can use to great effect. However, the ship is what I would call a "1.5" gun ship - at any given time only 1 of its main guns really matters. Flak can take down armor by itself, but any engineer can keep it up. Disabling the Gatling essentially cripples a Gat/Flak Pyra: it can't kill you, and can't disable you. It can turn, but with its sluggish response time this is an inferior option. The Gatling by itself is more of a threat, because it can and will take down armor and eventually hull. But without the Flak to finish you off you will still be MUCH better off.
But you say "Well duh, if you take out their guns, they can't kill you. So what?". I say: the Artemis is superior over other weapons to take out that Gatling because of its range, burst radius, accuracy, and constant pressure. It can take down the Gatling at long ranges, unlike the Carronade: this means that you can knock it out before it does major damage to you. It has a large burst radius, making it more forgiving of wide shots than the Mercury (it also does explosive so synergizes with gat). It is both more accurate and has more constant pressure than the Hwacha: even though the Hwacha can knock out an entire ship if done perfectly, it will often not knock out what you need. The long firing delay also means that the enemy can recover their guns.
Finally, the two Artemis' firing at once makes for an amazing ambush and support build. If a Pyra ignores you to attack your ally: you can knock out all of their engines very fast, saving your ally. Similarly if you ever get to the side or behind a Pyra in a brawl, you can knock out an engine. Since their main engie is pretty busy fighting off your gat, they have to either lose a top gunner or lose the turning battle. Heck, in a brawl if I'm between enemies I will sometimes jump off the helm to fire an off side Artemis. 1 volley that disables something can turn a fight, and with the gat/art's wide firing arcs you have the time.
There are however major downsides to this build.
1) You give up the forward Mercury. I think this is worth it on all maps, except maybe dunes. But even then I just make one side a double snipe, front and other side art/art/gat. Still, this hurts.
2) You don't kill as fast as flaks on the side. If you are in a situation when you need the quick kill (need to run to an ally for example) then you are out of luck.
3) Does not work with AI crew. One is... allright, but you won't be getting accurate triple fire. You really need a crew that knows how to shoot out components. They also better have mics so they can yell at you if (when) you turn the gat out of arc.
4) Its harder to fly than Gat/Flak because the Artemis has a miserable upwards traverse. Down is not good but ok, but you can't be very far below a target. If they knock our your balloon or are above you? Its going to be a bad day.
5) Its harder to captain. This is both because you must maintain triple fire whenever possible, and also because you are responsible for telling your main engie when to repair. The balloon is also your responsibility. Your engies are too busy firing to do the balloon/hull run unless your maneuvering engines are also down.
This is my first guide, so let me know what you think!