There was an infamous war game conducted years ago where a U.S. admiral in command of a bunch of speed boats and fishing boats sunk the fleet of a U.S. admiral in command of destroyers and etc. The former had numerical superiority so IIRC he just zerg swarmed and attached explosives to the side of the ships. The victory was completely one-sided, and it was so humiliating that they tried to suppress the results. The victorious admiral was given harsh words for making a mockery of the war game. Adm. Zhang made reference to the exact same strategy of zerg swarming with small fast boats and explosives, so he must be at least somewhat familiar with that war game. A lot of the small speed boats were sunk, but overwhelming numerical superiority won the day. The cost damage inflicted against the destroyers/other "serious" navy ships (they were all sunk) vs the cost of the speed boats, explosives, and men was exponential.