Let me get this straight. You expect Plo Koon to leap out of his starfighter and attack his own clone troops? Right when that first shot was fire from the ARC-170's, Plo Koon was done. There was no way for him to get out. He was in an even worse position than Stass Allie.
Plo Koon died to a Average Clone Trooper , Revan "Might" have died two 4 Above Average even Great Characters .
You see we have to put something else into this.
Revan like Vader, Luke , Bane , Exar Kun , Meetra , Kyle , Cade , Jaina , Anakin , is a MAIN CHARACTER not just a Character add that builds a Story .
Obi-Wan , less powerful and possibly less skilled than Plo-Koon survived Order 66 because he was Wiser and Probably much more Smarter ! If Anything Revan would have been that .
The attack on Obi-Wan failed miserably. If you watch ROTS again, you will see the laser blast from the AT-TE strike the cliffside, which knocked Obi-Wan off and into the pits. Yoda survived due to his masterful precognitive abilities and the fact that he could feel the simultaneous deaths of his fellow Jedi across the galaxy. The other survivors, I'm not too sure about. At any rate, Plo Koon was in a bad position in which he could not do anything.