So yeah, to elaborate, here's my main idea for a build right now.
Front gat
Left upper mine launcher/flare
Left lower flak
Right upper gat
Right lower flak
The idea here: when coming into an engagement, the top engi and right engi are on the gatlings, with the left engi on the hull/staying near the flak. Once the hull goes down, the left engi fires the flak and the right engi jumps down onto the right flak and fires it. The right engi handles balloon repairs if necessary.
So you're basically getting dual gats followed by dual flaks on the enemy ship.