We cannot forget though as mefit pointed out that the Separatists where being aided by Sidious, and of course Dooku. Without Sidious Grievous will find it difficult to execute effective strategy and will suffer from a lack of intellegence on enemy movements. He will also not have effecitvely a sabotuer on the other side. And without Dooku he will have difficulty keeping the Sepratists leaders unified and supporting him, as well as other Sepratists worlds which may abadon a cyborg leader. Most likely as the fight goes on he will be stipped of everything apart from his droids armies and his factories.
However he only really need the droid armies to win, he has a powerful enough force to attack Dxun and perhaps kill Mandalore if he attempts to protect it. Mandalore did after all participate in the Second Battle of Dxun during the Mandalorians Wars - he may not be so lucky to escape alive with Grievous' deadly battle droids rampaging over the moon. This is at least how I see the Kaggath heading. Fight me!
I guess I missed Mefit's point concerning Greivous's lack of Dooku and especially Sidious. This certainly changes things. That's an excellent point. With that in mind (and my previous points) I give a clear tactics advantage to MtU. This battle suddenly seems like it is in the realm of winnable for MtU. With a advantage in troop quality, ship quality, and tactics, MtU is gonna give an excellent fight. I'd love to see him beat Greivous. Although a victory for MtU now seems to be possible, I still imagine that Greivous will win by a bit.
Greivous's greatest advantage (imo) is his industry. What industry does MtU have? To the best of my knowledge he commands a army, not a nation. Armies are great for fighting and all, but in a prolonged war, you need citizens and factories. What citizens does MtU have? I imagine he has some slaves, but not many due to his bombard-worlds tactics. He can recruit soldiers and mercenaries, but they won't be of the same quality as Mandos. Also, I don't see how MtU is gonna create ships quickly enough to make up for lost ships.
So industry and recruitment seems to be a big problem for MtU. I saw someone mention something about Mtu having War Forges though? What are those?