I sometimes do that, that if I like the mechanics of a game, but think it's too lethal for 'adventuring' mode (where players are expected to keep the same character/space ship/what ever), I simply multiply the 'hit points' with a large factor for the players' gaming pieces, and by a smaller factor for the non-player gaming pieces.
I used the method on Battlefleet Gothic, once, havng a player starting out commanding a frigate, for instance.
That way, you can make otherwise lethal hits become lesser damage, keeping the main mechanics intact, but making things (and especially players) harder to kill.