It's a common thought the one that expects difficulty in F:NV to change with the your level. I'd like to clarify that a little here, since the thread deals with two different cases.
NPCs/Creatures in the Wasteland, in areas that are not necessary to vanquish to advance the critical path (read: the vast majority of the Wasteland), are not leveled relative to you. They are also not spawned from lists that change according to level. They are what they are, consistent, and persistent. You may notice that remote, harsh locations (mountains, areas far away from urban centers, etc.) tend to be inhabited by creatures much more fearsome than those found in relatively "tame" areas of the Wasteland.
In contrast, enemies that appear along, or at specific challenges of, the main quests' paths will change in difficulty depending on your own level.
So, while the Legate indeed changes difficulty depending on your strength, Deathclaws at Quarry Junction will not.
My advice? The Legate is a tough-as-nails man. Use every trick in the book against him, and you'll prevail.
O.
I say screw the level thing I set the Diff slider to very easy because wanted a casual experience, and to get the story, This guy is about as casual as a wire brush attachment on a power drill up the wahoo. Very Easy? --my aforementioned wahoo!!!! I didn't expect a cake walk by any means for the final battle, but this is silly. Once again Devs forget that very easy to you guys equals hard to the casual gamer.
Alone this guy would be a tough fight--with his guards?!?!?!?!--say didn't I have an army or three on my side??? where the blazes are they???
And since there is no way to spread your points to make a combat and social monster with out sacrificing everything else all is can say is ---so agreed with OP----REALLY!?!?!?!?!