I was just thinking that supply ships could be an interesting mechanic to add. You could allocate resources to them and set a rally point then let the computer build and send them. You order your fleet to come near the supply ships to resupply, the fleet then gets a bonus in terms of firing speed and health and even morale as all food, ammo, maintenance and other victuals have been restocked. The ships are now at maximum efficiency. Once resupplied and away from the supply ships the fleet degrades back to normal levels and efficiency decreases over time.
Supply ships would run out of supply slowly and there would be a button to return them to base and restock. before automatically making their way back.
Supply depots could also be a thing.
Conquest frontier war had supply ships and it and was successful with that mechanic. Supply ships were very important in that game.
Major point of difference from the first sins this wwould be.
……….lines of communication:………….
This means that when a ship is cut off from its own lines or in enemy territory it is slower to respond to your orders unless subspace tech has been researched? Alternately you might need a special comms ship to ensure permission to strike other systems and initiative levels are allowed for local task force leaders?
ok this idea is half baked for me at the moment. But its based on captains having speciifc order parameters when leaving for deep space or enemy territory outside of easy comms range. It would rely on whoever you had in charge of the fleet as well.