Your solutions are more big ship vs small ship and don't address the problem at its core.
With that, I'll just copy and paste myself here:
Chainshots are the most powerful PvP tool in the game. Ask anyone which of these they'd prefer in their arsenal: chainshot, Wraithball, or Cursed Cannonball...you'll 100% get chainshot voted as the holy grail PvP tool every single time. On top of that, with the right RNG, I've left outposts with easily over 20 chainshots at times...and then collect even more in floating barrels and shipwrecks as I go. Wraithballs are incredibly powerful, yet for some reason are tied to completing Flameheart. Why would (arguably) the #2 most powerful PvP tool be tied to an event and not the #1 most powerful?
Here's my suggestions...the first option rewards those who are producing loot on a server with the ability to better defend themselves. The second one would work to balance the power of the chainshot. One or the other of these options, not both.
-1) Tie chainshots to completing world events. This would be my suggested breakdown of chainshot rewards by event:
-Skeleton Sloop (roaming or part of fleet): 2-3 in storage crate
-Skeleton Galleon (roaming or part of fleet): 3-4 in storage crate
-Skeleton Fort: 3-4 in a supply barrel that would be added to the fort vault...throw a couple premium food items in there too.
-Ashen Winds: 3-4 in a storage crate that would rise up like the rest of the loot...throw a couple premium food items in there too.
-Fort of Fortune: 5-6 in a supply barrel that would be added to the fort vault...throw a couple premium food items in there too.
-Flameheart: N/A because it produces Wraithballs instead.
-Megalodon: 1-2 in a supply barrel that would float up.
-Kraken: 1-2 in a supply barrel that would float up.
-Treasuries: 2-3 in a supply barrel that would be added to the treasury vault...throw a couple premium food items in there too.
-2) Only allow for ONE chainshot to be in the pocket of any player at any time. This means you can fire one, then you'd have to grab another or swap with another crew member. This one would force crews to be more accurate with their chainshots instead of just being able to send a rain of helicopters hoping one hits...which against a sloop, is all you really need.