Oh, well, a lot of that simply wasn't focused on in the graphic novel, so we can't be sure of it, but i see what you mean. However, outsmarting Doctor Manhattan is a significant feat, as is creating the fake alien monster and tricking the world in to peace. Ozymandias may have limited feats but those feats are definitely comparable to some of the plans Luthor has concocted. Also, Luthor tends to lose, while Ozymandias has, technically, a one-hundred-percent sucess rate.
A lot of the problems with comparing these two chracters are due to the lack of one of them, Ozymandias, being in mainstream comics, or, at least, more comics.
"outsmarting" Dr. Manhattan wasn't as impressive as you're making it out to be. Primarily because he didn't actually "outsmart" him. He found a minor weakness in his(manhattan's) powers, and used that weakness to make sure that Manhattan didn't know what he was doing -.-
A comparable thing, would be Luthor beating Superman in a fist fight. After weakening him with Kryptonite or Red Sunlight.
Though I will admit, that convincing Dr. Manhattan, once he found out what was happening, that it was a good idea. That was moderately impressive.