Bandits fighting to the death always strikes me as profoundly stupid.
The moment they realize they're outmatched, they'll flee. If they're more evenly matched, they're still going to flee when it doesn't go their way.
Bandits steal to survive, kill when resisted when they can get away with it, and most importantly regular bandits will not attack a clearly fully geared, armed, and armored party of 6
If I'm the DM if regular unaffiliated bandits are attacking, there's a "reason" behind it that makes sense other than "oh no random highwaymen"
It's a minor pet peeve but I'm glad I'm not only person who thinks about realistic encounters.
Except the anti-metagaming tarrasque. That's an extra dimensional being who doesn't follow logical rules. Like meta gamers.