I was wondering if this was covered somewhere.

In F3 and NV companions HP were increased also as you increased the difficulty level, which was in my opinion a bug or at least very bad idea.

As I like the challenge and I mostly play on hardest difficulty, this "feature" just forced me to not use any companions because the game was getting very easy.

I hope that this was addressed in F4 and that they won't be doing the same mistake again.

Nope, the only official info we have is the fact they can't die, everything else is unknown.

I want a mod to nerf Dogmeat and allow me to have another companion besides him.

I don't need him to be a combat monster, but letting me know when trouble is coming is very useful.

You don't need to nerd Dogmear - you can simply dismiss him and get another companion

Anyone able to provide info about companions vs difficulty.

It at the moment I am going with Codsworth on survivor and he cuts through everything without problems.

I am not sure but I guess his HP might be upped by the difficulty also...

Anyone can confirm that?

So I did a test.

It took me 4 frag granades and something like 200 bullets of .38 from one of the first machine guns to make Codsworth to go unconscious on survivor.

On very easy it took me 50 bullets of .38 from the same gun...

Great, so another Bethesda game without companions because of this NPC hp nonsense...

Bethesda, Bethesda never changes.