My real problem with the NCR in the Mojave is their equipment. Let's start out with the most obvious problem in that on a solider to solider level they have at best AR 15s and Cowboy Repeaters. That would not be a problem in today's world where yes a bullet to the head ends in death, but considering those weapons are not as powerful, why in high hell are they not using more powerful small arms weapons?
The NCR does not even have an excuse for not using those weapons considering the Gun Runners are based out of the NCR! Once you add in the Gun Runners Arsenal and massive amount of mini-nukes that we know are existent and for sale on the frontier of NCR land in the Mojave, one has to wonder how large the Gun Runners Inventory is back in California. Seriously a few troopers equipped with Fat Men could change the whole pace of battle at say Forlorn Hope, Nelson or the Dam. With just a proper weapons upgrade the NCR could have good enough equipment to cross the river and remove Caesar from the Fort. Even Legate himself falls to the might that is a Fat Man with a Big Kid Mini Nuke inside.
Then there is the Air Force. The NCR has working power armor and a bunch of tribals in at Nellis can fly a plane and yet the NCR does not have ONE bomber to spare for the final battle? Hell just think they could just load the bomber up with mini-nukes and drop it on the Legion camps! There you go an end to the war! Hell even a Vertiberd with two guys shooting mini-nukes at the Legions camps would basically win the damn war. Does the NCR really not have ONE vertibred or bomber or a [censored] hot air balloon to spare? Seriously?
One more thing, whatever happened to artillery? Did the NCR keep the ability to restore power armor and train power armor but lose the simple ability to make working artillery?! Hell where are the mortors? [censored] Caesers camp across the river, let's see those tribal savages take the Dam while getting bombed from above.
To be frank I think the way the designers of New Vegas had to cripple the NCR to much to make the war make any sense. I have a hard time believing the NCR would not have used any mini-nukes, better small arms, air power, or artillery before or during the second battle. And NO one in the military including there best and brightest you talk to even think about doing any of the aforementioned things to win.