Exactly, Sluggo. But, that's WHY certain characters should be condensed. To give the saga more unity. And actually, contrary to your opinion, it's actually simplifying things. Why do we need to have a different villain every movie until we get to the OT?

These are the reasons we decided to do this:

-Maul didn't have a big enough part.

-Greivous came out of nowhere and was a p*ssy. An extremely dull and mishandled character.

-It strengthens the drama in episode III between Greivous and Obi-Wan and possibly Greivous and Anakin.

-It doesn't matter that they don't walk the same, he's in a mechanical suit! Besides, their eyes are very similar.

-It echos Vader's situation. We can assume only Sidious has this technology and keeps it a secret.

-Remember Palpatine can sense when his apprentice is in trouble. Palpatine was ON NABOO in the following scene.

-Plus, it might be a bigger draw for Anakin in Episode III when Palpy is talking about saving Padme, Anakin has already seen that he has the power to bring his apprentice back from the dead...

Why NOT do it? Why have a completely new character who contributes nothing to the story come out of nowhere in episode III and basically serve no purpose whatsoever?