I've been reading lots of reviews here.

Some seem to miss the fact that there is a big difference between the legend being told in one book, and the real story that happen for real.

You must understand that the Saga developed on a 200 century time base. And just like in reality, story tend to change over time, specially if it is being pass orally, like in Dune.

What you take for mistakes are in fact voluntarily put there to make it more realistic.