I barely die on normal level but every now and then some guys manage to kill me. Klingon sword masters , sometimes even Breen. I have to admit i am too lazy to switch armor and tribble buffs. Swords do kinetic/physical damage, putting on the right armor helps and you should keep stunning them. Phaser stun pistol (Tos Type 2) and an exploit weapon (Tos rifle) works. Always staying with your group (medical tricorder range) is another advise. I know it's hard against Borg or Swordmasters approaching you.
I usually start with tossing a photon grenade (stun/knockback Tac ability) to get me a few seconds extra. Using "fire at my target" is good to take out the boss fiirst, i usually diminsh the overall threat first by killing the weaker ones.