Artemis is a bit tricky. It is kinda important to have all roles filled, especially at higher difficulties. Knowing what frequency an enemy is set to can be the determining factor of winning the overall battle because it saves time. Ultimately the most important resource in Artemis is time. Comms can send requests to starbases to allow you to dock and have double energy and weapon loading for a bit of time, as well as ask enemies to surrender (saving you time killing them, and saving you energy and munitions so you don't have to go back to base, which takes time). Science can let you know what frequencies are, but more importantly, they are a second set of eyes that view the map and can point out immediate threats and those that can be dealt with later. Engineering is incredibly important because if they manage energy correctly a good engineer can keep a ship going 2x or 3x longer before docking than normal (and depending on map settings, you may never have to dock for energy if you have a decent helmsman and crew that point out artifacts), as well as get you places faster and do more damage, allowing you to save time docking, moving, and attacking. Helm is also important, because if they can stay out of enemy firing arcs but keep the enemy in your own arcs, you save energy recharging the shields and time maneuvering to attack. Weapons can manually target ships and take down certain enemy systems, which can keep you from being shot at, or keep an enemy from regenerating their shield. It might seem like energy is the most important resource, and it is definitely up there, but time takes the cake. With one ship on most scenarios at a high difficulty level it is basically impossible to not lose a base because there is simply not enough time to kill every ship before bases come under attack. At low difficulties there's plenty of time to do every job yourself, but I'd say much past difficulty 6 or 7 unless you have been playing for a while everything falls apart without a crew.