This is not a real problem.
Have you tried to force people to with one-handed weapons and shields to respect "your turn" in combat with a menavlion? When you're getting attacked by a 1 hander at close range, it feels way too slow if you've ever had to use it against a competent player at close range. But if someone with a menav is feinting against someone who doesn't know how to block at all, then it might seem like it's "too fast" or unbalanced. We are speaking, by the way, after the menav has already been nerfed hard--mentioning this if someone is reading in the distant future. Of course the menav is one of the slower 2 handers.
Are you personally successful when using a 2-handed weapon against someone with a sword and shield? My anecdotal experience is that the people who complain the most that 2 handers are easy mode are generally the ones who never use them because they can't block without a shield. You're overestimating how useful a reach advantage is when people with shields can easily get within and stay within reach and facehug you. If someone is consistently beating you with a 2 hander the odds are they would consistently beat you when using a sword and shield.
Players can sometimes use combination of footwork, feints, regular attacks, and predictions of when their opponent is going to feint to get a hit in when it's technically the other guy's turn to attack, one handed weapons are objectively faster so the only one of these where the 2 hander has an advantage is in distance and damage. Go play skirmish mode for a few rounds with a 2 hander, then a few rounds with a sword and shield, tell me which one you personally score higher with and then tell me your conclusion about which one is easier to play with.
Miscellaneous note but the alternative use and absence of hyphens with the compound adjectives here is intentional.
firstly i dont wanna go to a **** measuring contest, i was long time ago one of the best player in oceanic region, i mention this only is to justify i understand the basic combat mechnism of the game.
secondly my experence align with hoonli in skirmish mode, in team battle with class movement speed boost and directional shiled blocking which introduce in bannerlord, combine with reach buff about 30%-50% across the borad compare to warband, make it insansly strong in small group fight, ofc in more orgnise clan fight shielder can easily isolate and fast kill 2hander by exploit a simply fact that 2h cant block 2 attack at 2 direction. but again am not talking about clan fight, am talking about average solo queue skirmish experence. movement speed in my opinion is something should alway be equally among all classes , it affect way too much on a game that base everything on positioning and speed.
if am in a last stand 1v1 situation and the other side depand on the weapon for example menavlion, you have to ditch your shield because 1.it will get break very fast 2. the moment speed penalty from shield plus class different make you impossible get in a strike position. if you let a shield raised opponent get in closed range with 2hander class you simply have no idea what you are doing, and even you get closed enough, kick is still very powerfully tool as defence measure since heavy with shield dont move well at all.
and lastly crushthrough, if you do a 1h against 2h in current patch, crushthrough is something you have to take into account it's still happen way to often in a dueling situation, and group fight with certain weapon again such as menavlion it can practice crushthrough in a literily unpunishable range.
damge is something can not be ignore as well, most 2h can 2-3hit all heavy infantry, that if you take a archer class often will land one shot pior to the engement then it only require 1 hit to close the deal, the archer's projectile speed i didnt check but feel way faster in warband as result make it easier to land and more dmg... yes if you chose archer you give up on class speed boost, but archer with acess of 2hander is way too much of utiliy.
the title is for eye graping. the problem for me is many of game decison is not theortically sound, current skirmish is repetive to said the least. you know the outcome just by looking at the class people take. what i suggest of 2hander is to make shock troop only good at small group fight, ideally give them real shield and 1h weapon, and deny the access of archers 2h weapon. Because so far with eveything as it were, certain senario in skirmish feel very depressing. if you can come up with better solution am happy to hear it.