As the game currently stands, engineers dominate the crews of ships due to their superior versatility in comparison to gunners. An engineer with a decent ammo type and the buffing tool can do much greater damage to an enemy ship than a gunner, and can still hop off to extinguish fires or repair parts as needed. Is it still possible to do well with 2 gunner crewmen instead of 2 engineers? Yes, but it is much more difficult and requires a lot more luck and a better metagame.
What can improve on this design? Nerfing the engineer doesn't sound like a good idea and would probably only make people upset. Perhaps a change of some kind to gunners that adds a little more functionality to them? Something that makes them useful enough to want to use? Yes!
Currently, the gunner gets to choose 2 additional ammo types and can therefore man a variety of different guns with competence, but that alone does not add enough to justify their lack of repair tools. I propose the addition of new gunner specific utilities that ONLY gunners can use:
Damage Converter: An ammo type that converts a portion of the weapon's damage to a different type, thus allowing gunners to tailor the gun to suit a new purpose. This would be difficult to implement and balance, but could be very interesting and add new strategies to the game.
Examples:
-Galleyman's Surprise: A dash of extra spice to every meal does wonders! Add in a few kitchen utensils to liven up the party! Converts 30% of the gun's damage as Flechette damage, +15% bullet drop.
-Positronic Shells: The unique qualities of this ammunition housing disperses magnetic shockwaves on impact, devastating equipment struck by it. Converts 30% of the gun's damage to Shatter type, +15% weapon recoil.
Ability Augmentation An ability that buffs a gunner's usefulness at a particular gunning aspect similar to pilot abilities. These would be chosen while not manning a weapon so as not to confuse them with ammo types.
Examples:
-Iron Instincts: Become one with the metal. Reduces the damage taken by weapons you man by 35%, +5% weapon recoil.
-Tekno Logic: Load it, check it, turn it, zoom it. Reduces reloading time on manned weapons by 25%, -10% weapon damage. Yeah, yeah.