Duelling in bannerlord will be unfulfilling until the issues with the footwork of the game and time to block are resolved. The footwork is so bad and rewards (and once people learn kick-slashes, downright forces) kiting, that duelling is largely pointless. There is nothing in the movement system at the moment that forces people to even be in a fight at the moment, forward movement is not significantly faster than kiting while attacking movement. Speed is close to being omnidirectional, and barely affected by attacking, using ranged weapons or holding attacks. It makes little sense that a player can move away from a player while holding an attack faster than a player just moving forward at them. But they can. With this movement system, there is nothing a melee player can do to force a duel without an objective flag to aid them.
I think Mordhau has a great combat system, but I don't think it's comparable to Warband's. Blocking is basically just based on timing, no directional blocking involved, there're different mechanics and it's great combat for duels, but I doubt it is objectively superior to Warband combat.
Mordhau's combat system has a lot of issues that are very distinct from the issues that bannerlord has, but are still very game-limiting.
The problems were largely:
Pings above 50ms would mean you directly take 30% of your hits directly from red parries, i.e parries that did not reach the server in time. It is a game that only functions properly if you can get 30ms latency or less. People below 30ms latency also were allowed to double parry attacks they fell for far more frequently than people above 50ms. It's to the extent that players at even just 55ms latency need to play with a completely different combat logic.
Initiative is determined too much by getting successful ripostes, to the extent that the outnumbered player in a 2v1 can't get initiative purely as the enemy can deliberately miss to prevent getting riposted. Essentially hitting a wall next to someone in a 2v1 is enough to kill them.
Stabs were unreadable, which in this context means that all you had to do for an unreadable attack was stand in someone's face and scroll up. They could be chambered, but the stab could be morphed or dragged, putting the defender at a large stamina disadvantage for low effort.
As reading accels/drags were largely enabled by footwork, light armour became extremely broken as it enabled you to footwork to the extent that you wouldn't need to read that hard at all.You could just footwork any attack that was dragged or accelled by a heavy armour user. This is made even more akward as one enemy miss is generally enough to win on stamina. I believe this is something that they're still trying to address
The existence of unreadable attacks in general meant that to some extent the game was always probabilistic. If an unreadable attack is performed against you, then sure, maybe you shouldn't be in that position, but it also means that you could just luck your way out of it by guessing the correct outcome. This went even further where even things that were considered bad decisions ended up winning fights. For example if you fall for the morph on a morph feint and early parry, you often won because your bad play (falling for the morph), led the attacker to lose stamina.
Regeneration broke skirmish as people could just stand out of the fight and regain health.
I played it to the extent of being a middle-level comp player, so I am not perfectly authoritative, and the above information is probably 3 months old now, but the game is definitely not superior to warband on any basis.