Super Mutants with rocket launchers tend to 1 hit everyone.
I actually made a semi cheat mod for that.
The idea behind it is that Katja Ian and Tycho during their level ups gain hit points equal to what would they gain after four levels based on vanilla "2 + EN/2" formula (ofcouse based on their EN) so tycho and Ian since they have 6EN gain 4x5hp=20 hp/lvl and Katja has EN=5 so 4x4hp=16hp/lvl this way:
IAN 50=>70=>90
Tycho 60=>80=>100
Katja 39=>55=>71
Up to this point the mod should be legit
the cheat part about this mod, is that I've set their player friendly Skills ( weapon, Healing, Utility,[but no barter no steal no speech]) to 200 so that shooting me in the back is no more.
they can even take out few Super mutants by themselfs, given they all have power armor and a decent weapon. Besides there are enaugh power armors in the game so that they all wear one. (4 PA total) Just remember to choose proper option in FIXT installer before applying theese (can change armor + all weapon animations for all of them).
I haven't uploaded the mod anywhere since nobody was interested in it. if @Sduibek will show interest he may recive , modify and implement my mod in the FIXT be it improoved current or next release.