CMM is more like an expansion pack than a "Total Conversion", as it expands every aspect of Homeworld 2 with out losing its origonal feel.
I added in 2 new ships for both of the stock races. For the Vagar I created a Swarmer for them and a Sniper corvette that can chew away at capital ships from a great range.
I've made the Keeper a playable race and reprogrammed the AI to get it to work correctly. The Keeper builds all the different types of ships and attack and defend just as the other two races.