Some things you could do:
- Put some more limits on using Gard to deflect/absorb injury. Say at a failed defense roll, you may only take up to half the damage on Gard.
- Make it more punishing to fight multiple opponents. Either give a big ganging-up bonus to multiple attackers or a minus to multiple defense rolls.
- Critical / major injuries. Say any injury that does half of your full Hälsa at once is a “Major wound” with some extra effects. Major wounds take longer to heal than common injuries.