When playing in a Multiplayer session, adjust all difficulty-relevant settings to the host's settings, so everyone has the same experience:
Visual:
- UI elements lile minimap
- Map / minimap icons like enemy presence clouds
- Detection indicators
- Enemy markers (crosscom UI)
Mechanical:
- Same damage levels (dealing and receiving)
- Same injury/healing rules
While I agree this idea has merit, if matchmaking was done like this, players who don't like the hosts settings would simply leave the session, making it hard to keep a full squad together.
To have every player use the exact same settings as the host, you would have more luck filling a squad with friends who play the same way you do.