Some changes to battlefield duels:

-Rulers who employ Bodyguards can now no longer be targeted for battlefield duels unless their Bodyguards are a) not present on the battlefield b) already engaged by another enemy knight or c) heavily wounded (except if the ruler is being attacked while not leading from the front, in which case heavily wounded bodyguards may still defend them
-To support this change, knights and commanders employed as Bodyguards can no longer be the attacker in battlefield duels if their employer is present on the battlefield.
-Rulers who get a chance to attack an enemy knight now have the option to send one of their available vassal knights to do so instead. Their bodyguards are not eligible to be an option here.
-There is now AI logic for AI knights and commanders to choose between attacking an enemy knight, sending one of their vassal knights, or retreating.
-Some Royal Court compatibility fixes - in particular, holders of the Garuda Warrior court position are now much less likely to yield in battlefield duels, as their flavour suggests.

-Fix to Better Battles compatibility - certain BB events (mainly the Black Knight) were triggering too often.
-Characters whose deaths would invalidate the relevant war (mainly, peasant/populist revolt leaders) can no longer be killed by the random death chance in a duel as an anti-frustration feature. You can still CHOOSE to kill them afterwards (AIs are less likely to kill them, or any war leader, unless they have somehow become their rivals/nemeses) but this should cut down on that problem.

Compatibility update:

Compatibility included with Better Battles and Traditional Tenets/Medieval Matriarchs (load this mod after them).
Nothing should change if you are not using these mods.