when I did my reformist campaign, I took as much land north and east as I could, I took out the Rangers before they joined NCR and I had a solid frontline against them, after that I just held, when I had enough troops and rebels raised up I attached shady sands. Also air power is important, you can get really good CAS early and stock pile it before the war. It is a very hard campaign and it took me a few play throughs just to take the NCR out. after that its still difficult.
my advice, of you want to play test the mod go for the state of Nevada focus, still incredibly strong and fun to play as.

Thanks, Micangetric! I managed to get through after a few playthroughs; the trick seems to be getting their attention split as much as possible. I got lucky, when they got hit by the brotherhood first, and I was able to pull the Desert Rangers in, too. Enough vectors and there she went!

And the massive march of American troops across Arizona was /awesome/. I also agree, there is a lot of fun to be had with State of Nevada, too!