I've been following this thread for a long time but didn't find the time to post although I have a lot to say.
There is a few classes/units that I like a lot in the game when it comes the look, especially Aseraï veteran and beduin, Khuzait lancer and guard and Battanian horseman. But overall there are too many flaws: anachronisms, clichés, inconsistensies and ugliness. Warband often did better to be honest.
While suggestions made on this thread sometimes improved some of these aspects, they sometimes also worsened them, especially when it comes to anachronisms and clichés.
Let's start with the vanilla design.
First, I don't understand why the devs said they wanted to portray the Aserais as pre-Islamic Arabs: not only does it no fit the timelime of Bannerlord (8th-11th century/late Dark Ages) but also we barely know how Arabs looked by that time. Thus it's not a surprise that Aserais ended up as clichés of medieval "Saracens", wrapped in some muddy leather to give them an older vibe.
Clichés among Aserais are mostly the conical helmets, the curved swords and turbans wrapped around helmets. While all of these existed, they were not that widespread, especially in the timeline of the game. I think all of these elements should be limited to one class.
Mamluk's helmet is particularly unoriginal beside being uglily made, which is a shame for such an important class/unit. Guard's "donut armor" are downright hideous and quite unrealistic, I don't even understand how such a horrible thing made its way up to the beta. The adarga is a great and original idea, however it is anachronistic, at least in this bivalve shape which appeared in the 14th century (and lasted up to the 19th century in Mexico).
By contrast, Veterans are a great example of a well-done class: they don't fit the Saracen cliché, they mostly fit the timeline and they are beautiful. Beduin are also a great looking class - yes they are cliché but clichés are not necesarily inaccurate.
To conclude with the Aserais, I think the devs should dump this "pre-Islamic Arabs" nonsense and freely take their inspiration from the 8th to 11th century Arab empires from Spain to Persia, which offer rich and various sources of inspiration.
Vlandians are almost totally missed. While I expected some Norman/early feudal looking warriors, we got something barely different from Warband's Swadians. Because the devs mostly based them on 13th century Western Europe: kettle hats, coat of plates, transitional helms, heater shields, mail caparisons & cie. Talewords, seriously..?
The Bayeux Tapestry would have been an amazing main source! Combined with others from all around Western Europe up to Norman Sicily for some exoticism, we could have got something fabulous. Instead, we got copies of Swadians, again filled with some ugly leather to make them look older. As said above, we did not even get the siculo-norman helmet of the game cover...
Although it's anachronistic, I still like the sergeant design (around 1200 AD). But it would indeed rather fit a knight. Also it has a big inconsistency: why isn't the hood worn? Normally you put something on your head (hood, mail coif or whatever) then your helm. Why would one removes his hood before putting his helm? It makes no sense at all and isn't convincing aesthetically. Same for sharpshooter's 10 cm thick shields. The knight's faceplate helmet is rather ugly also, which I regret, but anyway I think Vlandians should be remade from scratch.
(Don't have the time for the other factions, anyway I'm less qualified to speak about them.)
Now in regard to the suggestions, congrats to all those who posted theirs. I was very impressed by some, especially from Terco_Viejo.
But again, too many clichés and anachronisms. I've seen the Khula Khud type of helmet suggested several times for the Aserais on the thread: it's the most cliché Islamic helmet ever, and is actually an Indo-Persian model dating from.. 17th-19th centuries. Again for Aserais, suggestions with all the classes/units having a turban wrapped over a conical helmet, Ottoman armors, etc.
For the Empire, always suggestions for armors and equipments belonging to the Classical era (see just above my post).
For the Vlandians, late medieval knights (last post of the previous page for example).
Etc.
You guys should rather stick to sources closer to the game timeframe, don't make it even more inconsistent.
I'm short in time, but I hope my post is enough clear. Will try some suggestions later.