The problem isn't just the swarms, it's the entire design of the dropship.
We're trying to have our cake and eat it too with the current design of the dropship. There are four primary factors which contribute to the dropship's balance current balance:
(1) How survivable is it (decreases risk)
(2) How much damage can it do? (increases reward)
(3) How much does it cost (increases risk)
(4) How much other utility does it have (increases reward)
There is no way to balance the dropship so that it is both survivable and it has good damage capabilities. Why is that?
In order to keep risk/reward within acceptable parameters, if you make the Dropship more tanky, you must make it cost more ISK. No matter what, a Dropship will always have the utility of troop transport. If it is tanky, and passably maneuverable, then it must cost more. Otherwise, everyone would always have a dropship: there would be no reason not to have one. It's the same kind of logic that goes into the LAV "spam" produced by free LAV BPO's. The less it costs, the more "why not" mentality.
Meanwhile, the more weapons capacity you give a dropship, the more potential reward. Some risk or another must offset this, so either you have to decrease health or increase price in order to achieve some sort of balance.
Right now, we have a bit of a problem. Swarm Launchers being unable to hit dropships effectively boosts the HP of dropships for the time being. Yes, they are forced to fly in a circular pattern, but it seems that the weapons are still effective while flying in this pattern, at least on smaller maps. This situation is actually great, because it shows exactly what's wrong with the current dropship design.
Dropships have good weapons, good tank, and are at a price which is profitable granted those two factors.
The problem with dropships is that their current balance insists on them doing all the air things at once.
http://cdn.memegenerator.net/instances/400x/28487752.jpgDropships right now are troop transports and weapons platforms at the same time. Meanwhile they're priced like they're troop transports without weapons capabilities.
If the swarm launcher is fixed in any way, the dropship becomes obsolete. Why? Because suddenly it just costs too damn much for how risky it is to fly one of the things onto the map. The weapons on a dropship aren't good enough to justify a 100k+ ISK cost that you're almost guaranteed to lose to any idiot and his swarm launcher.
If the EHP is left as is on the dropshiop, the dropship is overpowered. Why? Because it has the potential to do a lot of weapons damage for very small risk, since killing the things is so damn hard.
The core of the issue is that CCP hasn't made a decision. Is the dropship a troop transport, or is it a weapons platform?
If it is a weapons platform, it needs to be cheap, be relatively easy to kill (though not TOO easy, mind), and it needs to be able to do quite a bit of damage during the time that it's alive. Being cheap and fragile is essential. This way the risk isn't much, the reward is potentially high, but it requires a skilled pilot in order to maximize the reward you can get out of the dropship since it can be killed easily.
If it is an actual troop transport, it needs to be tanky, about the same price point that it is now, and it needs to have limited weapons capability.
CCP keeps on trying to combine weapons and tank in the same place. You'll never be able to balance that, especially IN THE AIR, which is worse than on the ground. The weapons make the reward too high compared to the risk, which is relatively low. This was the previous problem with tanks- they had great weapons and were really quite hard to kill. It didn't matter what the price point was, because they simply never died.