Ok, here's a run down, then and now:
Pranging the city adds to the rebuild time of the HQ and factories.
City totally down (shows 0% in status page) makes rebuild on factories and HQ 2hours.
Pranging the factories adds to the rebuild time of that particular supply at the fields.
Any fuel tanks at fields destroyed while the refinery is at 0% take 2hrs to come back. Holds true for all supplies:
fuel tanks - fuel refinery
barracks - troop training grounds
ammo bunkers - ammo factories
radar dish - radar factory
AA guns - flak factory
With a well orgnized group of 20 to 30 pilots you could almost literally ground a country. Wipe out the cities, then the factories, then the field supplies. All that country can launch with is 25% fuel, no troops, no bombs/rockets for 2hrs.
Now this is pre-1.08 strat.
1.08 added supply trains and convoys to resupply areas. This means taking the depots to stop the convoys (can the trains be stopped other than attacking the trains?).
Supplies can also be flown/trucked in with the C47/M3.
The ability for players to resupply targets nearly negates the usefulness of hitting the strat targets, save hitting them for scoring purposes. To wage a "strategic war" in the MA (something the MA wasn't designed for) your first move would have to be stopping player resupply of targets. Means city-factory-barracks at fields. While you're doing that there are 5+ supply trucks/planes inbound to the cities before you can get to the factories, negating the strike.
Now that's written a book (and sit wondering why
), the short answer to your question is:
Strat targets aren't worth much anymore, other than raising your buff/attack scores (and vehicle if ya want to drive to a strat target).
One night our cities were at 0% and our HQ was taken down. 20-25min we had full HQ/radar restored by 2 M3s and 1goon delivering supplies to the HQ. Cities were still at 0%. 5-7min flight for the gooney bird. 3-4min drive for the trucks.