I do not mean for AI fleets to have to actually calculate the amount of current fuel or supply they have. Calculating how much supply and fuel they need for X distance travelled, or Y amount of days for a patrol should be enough. Meaning that the system does not have to actually keep track of their resources, but only has to make a check once they are deployed.
Something like making a calculation, that if a specific amount of ships are going somewhere, then what would the cost be in supply + fuel to make a retour trip. Or, for a patrol, making a calculation, that if the patrol was travelling for, say, 10 days in hyperspace, then how many supplies would that be, considering standard speed is used, and how much fuel.
Maybe it doesn't make sense though. Still, something like this would fix pirate raids from one to the other side of the sector. Same for mods' fleets.