[COLOR="DarkGreen"]IF your scenario plays out, you will find that not everything will go according to plan. Grievous can bring all of those numbers to bear on Mandalore's fleets. You overestimate Mandalore's fleets. Again we can visit the Mandalore Wars to see how his fleet fared against fleets of significantly fewer numbers than Grievous'. Once Revan joined the war, the Mandalorians were quickly pushed back and routed. Grievous not only has the numbers to do this, but the tactical know-how to do it as well./COLOR]
lol@ Ventress, if only we didn't have that pesky rule to stop that...
As for your points. I concede I underplayed Grievous's tactical ability. However, I feel (by virtue of being smaller) there is less and less reason for MtU to spread himself thin as he doesn't NEED to protect as much in order to support his army thus negating Grievous's ability to do so. Also, notice I never said MtU's fleet would ever engage Grievous's fleet a second time just provoke or shadow. It's only after the whittling away of Grievous's supply/reinforcements that he can actually attack Grievous head on. But his fleet can still do enough damage that when it pops into a system nearby, Grievous must recall ships to overpower in the event of a battle. MtU effectively stalks Grievous's fleet while smaller Mando raiding parties dismantle Grievous's powerbase from the outside. Grievous would be trying to track the primary fleet, direct assaults on lightly defended worlds, and defend his powerbase from constant raids and harassment. And If MtU even found an important world of Grievous's, we know he has no qualms about utterly annihilating it. (granted Grievous would do the same but I think Grievous actually prefers the full land assaults and conquest whereas MtU would just as soon burn the whole thing and be done.)
I think it's a standoff between the fleets till one side's powerbase is chewed to bits. While Grievous is smart, I think MtU will just control things too well in the opening stages and have the momentum allowing him to hack at Grievous who would HAVE to win a few battles against these small forces to placate the other leaders of the CIS (ultimate problem of a Confederacy, they're not always unified) This will set up much of the second half of my scenario.
Now Aurbere, I completely see how Grievous would win. He'd drive his forces hard in a huge swath of destruction across the galaxy smothering the Mandos with numbers once they have them located and engaged (actually an early WW2 German tactic and later American one). The thing with my scenario is that MtU would know this and take the initiative, keep the Mandos mobile and aggressive. If MtU went defensive he'd be buried under a few billion megatons of droid.