What an interesting take. It’s a bit off on a few details, or it exaggerates them (but that may be the result of the sources they are using)... and leaves out some of the best parts, for instance how Kamehameha actually captured his cousin.

They were more like advisors than generals.

How did the communicate though? Likely through a mixture of broken English and broken Hawaiian. If you read through the accounts of early sailors, they often paper over the fact that neither side of the beach really understand the other, that there was little cross fluency. Generally speaking, that would have to wait until missionaries showed up and made a concerted effort to learn indigenous languages and at the same time gave indigenous peoples a chance to pick up English through more consistent exposure.

In most trading relationships though, it’s oftne the islander, who is more experienced with the languages of the foreign ships that come, than it is the crew of the ship with the language of the island. So while Davis and Young likely did learn some Hawaiian and other ali’i who handled foreign trade did learn English, there were no fluent interlocutors at that moment— though over time fluency is developing on both sides.