I think suggesting, or brainstorming an alternative might be a useful thing for constructivity's sake, so here goes:
Here are what I think the criteria for a class system should be:
1. Maximise choice. Let players use the exact gear they want, within faction and "financial" limits.
2. Keep it accessible. The system must be well explained, and ideally intuitive. The speed at which you can equip yourself is also important. You should be able to choose what you want as quickly as possible.
3. Customisation! This is the big, high explosive pink elephant in the room with the Bannerlord system. Cosmetic customisation is simply a good, important thing for a game like this. Not only is it extremely popular in games these days, but it also is 100% suitable to the setting.
4. Maintain balance. The old money system was always good. The better, or more specialised the item, the higher the cost. It's also extremely flexible. You can give everyone the same set amount of money, or you can reward players for their performance (the best for casual modes), or even reduce your respawn amounts based on crossing price thresholds.
So.
1. Choice
As in Warband, a small amount of very broad classes really is ideal. High amounts of choice increase replayability, and let you precisely gear your character to your playstyle, or the situation, or even just to goof around and experiment.
There is literally nothing wrong with the Native Warband system in concept, and I really think it should've just been iterated upon. Adding more options is vital, and there should be as few "gaps" in the equipment selection as possible. Take for example the Rhodoks in Native. Their infantry can't select the Green Tunic over Mail. This means you have a huge gap between the Ragged Outfit and the extremely expensive Green Surcoat. These gaps should be filled both to keep progression (in modes that allow for it) more steady, and also to maintain better faction balance.
If Taleworlds wants to make modes that are "balanced" (and probably not fun), then those modes could always have a different selection of gear, or boring rigid classes instead.
2. Accessibility.
Of course, for starters, a simple tutorial would make everyone's life easier. Some simple tooltips and stuff to explain things also go a long way. In addition, things like saving loadouts and tagging items as "high priority" for when you can't afford the whole loadout would massively make life easier.
Naturally, this also means the loadout menu should be accessible out of gameplay, i.e. when you're not on a server, so you can design loadouts before you play. Default example loadouts would also make things much easier for beginners.
3. Customisation!
An actual banner system would do wonders here. Let players choose their colours, their charge, everything. Make the cloth bits that colour. You want faction colours instead? Make that a client-side option. Technicolor tutti-frutti armies were a thing historically, and they make players recognisable from a distance. In addition, different "tiers" of armour could have multiple variants. Say for example you right click the "gambeson" in the gear selector, and a drop down menu of the various faction-specific styles of gambeson pops up.
Finally, this I see as the most important thing everyone's forgetting:
Bannerlord has a bloody weapon editor! Let us use our own weapons in MP! At least in the non-competitive modes. This is to me the biggest no-brainer!
If there's no technical problem with implementing it in MP, it'd be such an incredibly awesome feature. Whether you want to design weapons to be perfect for a certain playstyle, ones that you think look cool, or just something funny/ridiculous, all those reasons are 100% legitimate.
The weapon editor should be accessible out of gameplay too, your choice of weapon bits should depend on the faction, and the price could probably be determined via weapon attributes.
I'm 100% convinced that custom weapons in MP would be a very popular feature.
4. Balance.
Again, the money system is fantastic and flexible. It should be the basis for Bannerlord too, not some class system.
The way cost and money function could depend on the mode. In some modes, you could have the old system where you get rewarded with extra gold for playing well.
In a mode with limited respawns, the more you spend, the fewer spawns you have.
In captain-style modes, the more you spend, the fewer soldiers you have. This means, by the way, that your bots should have your exact loadout. (There's a Native server where your bots use your gear, it's really fun and varied)
If balance is vital, then everyone could just have the same fixed amount.
If TW continues to hate fun, they can always have the more competitive modes use a rigid class system instead.
Would be cool if we could come up with a system that we would by and large agree is 100% better than the current class & perk one.
(And yes, I understand that TW said that they are staying with the current, seemingly awful system, but in my experience when something bites a developer in the butt enough, they suddenly become surprisingly flexible)