I don't know if it has been done on purpose or if it's quite buggy but at level 27 (~ 200 armor) i've encountered two draugr at the same time and there was a huge difference in term of efficiency :
The first draugr lord was waving an ebony warhammer at me and was doing quite normal damages ( 80-100 without power attacks). It took more than 3 blows to kill me.
The second draugr was shooting at me with an ebony bow with ebony arrows and was doing more than 210 damages with each hit ! It doen't sound quite logical to me and it appears that bow damages weren't calculated properly when 1.6 was launched so...

Useless to say that being killed in less than two arrows with more than 300 (health) at this level is quite weird and not really proportional to some powerful weapons like ebony warhammer, one of the more powerful in the game.
Perhaps this need some investigation, as good bows and good arrows as the same time can transform any creature into an utterly powerful killing machine.