Past simple for two immediate actions

How the difference between the past simple and the past perfect affect the meaning of these sentences:

At the final moment of his quest, he (had) accomplished what he had set out to do.

And here he was, at the end of his journey - he (had) achieved his aim.

To me, the choice of the past simple seems more adequate as the "accomplishment" and "achievement" happened, probably, at the same time as the final moment of the quest and the end of the journey.

The past perfect, on the other hand, would look at the whole quest/journey process up until the moment the character was at the time, which can also make sense depending on the intented meaning.

In (1), the use of at suggests that the accomplishment happened at the same time as the endpoint, and hence the past simple is more appropriate.

At the final moment of his quest, he accomplished what he had set out to do.

If the accomplishment happened before that, I'd use by and the past perfect.

By the final moment of his quest, he had accomplished what he had set out to do.

And here he was, at the end of his journey--he (had) achieved his aim.

The first part

And here he was, at the end of his journey

is complete. The part after the dash he had achieved his aim is an interruption which looks back at the entire journey, and hence the past perfect is fine.