I believe the current range of cannons in theirs automatic(as i cannot manualy set range) mode is simply too low. Apaches 30mm gun was able to effectively engage targets way over 1500 meters. Now in Comanche and Mi-48 engaging something over 1000 meters is very difficult(and impossible over 1500meters). Currently Mi-48 is using 30mm rounds, so engaging something at 2500-3000 meters shouldn't be impossible. Comanche on the other hand is using 20mm cannon, so 2000-2500 shouldn't be tough either. Currently a 12,7mm sniper rifle has bigger range than a 30mm cannon.