While Ceasar's Legion has a smaller presence in the Mojave wasteland, it's worth remembering that they control a much larger territory east of the river, where the game's map does not extend, and it's hard to say just how much power and how many troops the Legion has there. Still, I find it a little implausible that the Legion can pose a serious threat to the NCR, given their major disadvantage in terms of equipment and their aversion to prewar medical technology. I could buy them being more of a match if the technological difference were something more along the lines of conventional firearms versus high-tech energy based weapons, or even if Ceasar's Legion was using outdated guns like repeaters or revolvers while the NCR had "modern" firearms, but when one side is dressed in patchwork armor ripping off Roman legionaries and uses sharp metal blades while the other side has guns... well, realistically speaking, I'd say the Legion would need to outnumber their foes pretty badly to avoid being picked off before they could even get close. I guess maybe they'd stand a chance through superior tactics. But while some of the better Legion commanders might be able to bring in such an advantage, if they were killed off, then I'd say the Legion wouldn't stand a chance. Indeed, I recon that the Legion's leaders are the only thing holding it together, kill off the ones at the top, and they'd go right back to the squabbling tribes they were before Caesar came along.
Their more experienced troops hold better weapons. And the reason you see so many with melee weapons is because of Caesar thought them to relly on it as a fall back.
If the NCR was more commited they might actually pose more of threat. As it stands by taking the defence they are and have wasted their advantage.
The NCR has their forces spread way to thin. Their training is awful. The capital back in the Core Region doesn't give a damn about the units in New Vegas. NCR are not even able to protect pro-NCR caravans that happen to be right outside of New Vegas. The NCR are only in a position to defend. They are only able to 'hold the line'. They lost Searchlight, they lost Nelson. It would be a matter of time before they lost the other camps along the Colorado, because they are unable to receive backup. Very high ranking officers in the NCR are Legion spies. The Fiends and Great Khans are already allied with the Legion (prior to any influence by the Courier). The pathetic Fiends are even giving Camp McCarran a run for their money. NCR's intel is all jacked up thanks to
Spoiler Chief Hanlon who has also admitted that the Legion is going to win and wants the NCR to pull out
. There are more facts that show that NCR out in the Mojave is a weak piece of fail, but I think this is proof enough. All of which I have listed are all canon in game (most of which the NCR has admitted of themselves)
Not so much fail, but divided, both political and military.
Regarding the former side the politics back home don't favour the war and domestic interests is keeping troops and efforts there.
On the latter the Legion managed to get several hostile tribes to keep NCR occupied inside the Mojave and use the fact that they are strechted out to infiltrate even more.
The legion has little problems with this because they are ruthless against anything/one that doesn't conform and are ruled by a dictator.
As for their training, I doubt it's really as awful as people make it out to be. It might have become less with the need for new recruits, but accept for the 'Misfits' there isn't any real indication that the NCR troopers are worthless.
It's mostly the politics and bureaucracy that keeps them from being effective.
The opening cutscene.
Hanlon may have said that, But do you really trust him now?
Also, If it's true, Most of those are still part of the half.
It's not stated in the opening and given comments left and right they could have more and better equiped soldiers in the Mojave if it wasn't for domestic politics.
What evidence do we have that Legion Recruits have better training than NCR soldiers?
While the NCR had many under-trained recruits because they ware outnumbered they must still have their experienced core unites.
Do small time tribals actually have that much combat experience and warfare knowledge?
As Caesar says, the tribes were simply playing at war until he came along, how much could he change them -he was a follower.
They are trained from a young age and unrelentlessly. In general I'd say they are better trained than the standard trooper, if only because of the time they put into them.
The ordinary NCR recruit probably has a proper training, but with the way the war is going the Mojave is getting an influx of green soldiers fresh from bootcamp (perhaps even graduated early).