It's true that the sword one hit you yes, but that's totally fine because the sword has a high risk high reward playing style.
In addition, the sword has only what 4 or 5 hits anyway. In those sword-maps your best bet is to stick with the team whenever your team doesn't have the sword and try to defend or to get the kill trade.
As far as outsmarting goes, this is the 10 point shortlist I'm using for defense.
Some even can be combined for peak performance
- A sword carrier has to come to you it's not the other way around
- Most sword players hide in obvious spots, avoid those or preemptively grenade them
- Use the 'Mangler' for a 1 shot & 1 melee hit or 3 Headshot kill trade (this is in my opinion by far the best sword counter weapon).
- Use cover to your advantage, as an example, learn the clamber drop clamber when and where it's possible
- Stick to high ground, sword lunges can't be performed from below without hitting the wall like 95% of the time
- Learn and use curb slides to outrun a pursuing sword carrier
- Learn where and which jumps you can perform to decrease travel time and flank/lose the carrier
- Make use of ledged above to bounce grenades back behind you
- Use the grappling hook as intended in other words, steal the sword away from them
- Tactically time a repulsor strike
Most importantly:
Learn how to patience yourself and not be tempted to go after the sword carrier yourself... alone!