Agreed.

When defending his ad-hoc approach to the prequels and tinkering with the original trilogy, Lucas said something about these stories being retellings of the same myth. So I think we can't even read too much into the episode numbers. Each trilogy is a different way of telling the same story, and each episode has some myth-retelling within it, as well. It's supposed to be all mixed up and ambiguous and repetitive, because that's how legends are. Thus, the fact that the events of one trilogy must precede the events of another doesn't mean they are perfectly accurate, in-universe continuations of the same story. The lines between canon and non-canon are intentionally blurred.

The same thing happens in the Zelda video game series.

Looking at it this way is the only thing that keeps me from getting too bent out of shape about things like "...another world-destroying space station that needs to be sabotaged by scrappy rebels? really?"