Your third paragraph is the big point I'm trying to get across, actually! 3 did a lot of reintroducing and playing against type, yet also boxed into a new corner, for many subjects. Super mutants are present for some reason, but are also completely different, as a quick example. It's familiar yet completely different, it's aesthetically in line with the classics even if every element is subverted, and I'm not as much of a fan of that. I think it's better to either stick with the classics for such a reintroduction, or move beyond them and imagine new classic factions, New Vegas only works well because it plays off 3 and 1/2 for a fanbase of both.

Also not a fan that you have to side with them unless you decide to commit genocide, but that's neither here nor there.

1 is probably my favorite portrayal, but I like how 4 subverts expectations and I like how NV takes the issues of 1 to logical conclusions.