The current CrusaderBlade versions use hardcoded native Bannerlord troops. This mod allows you to change the CK3 -> Bannerlord troop mapping with XML files. A mapping for De Re Militari (quickly) made by me is available as an example, which could be used as a base.

Installation
Extract the archive to your Bannerlord installation folder, activate it in the Bannerlord launcher. Make sure to activate any Troop mods as well if you want to use them!

KNOWN ISSUES

• If you load a CK3 savegame with a battle active in the Battle phase, you need to wait one day before jumping into the battle, otherwise CK3 hasn't calculated the Men-at-arms bonuses/penalties yet and they won't be applied in the Bannerlord battle either!
  

NEW in 2.1.0

• Override unit stats easily of all CK3 regiments of the same type to force consistent balance between cultures! This can be easily configured using the new multipliers for hitpoints, armor and skills in Settings.ini in the Module folder. Configuration per CK3 unit type is possible in 'Units\StatsOverride.xml'
  

NEW in 2.0.0

• Changed troop configs from JSON to XML! You need to convert your existing configurations!
  

• Support for unique troops for EVERY CK3 culture!
  

• Support for ALL CK3 men-at-arms types! Including regional/cultural!
  

• Men-at-arms bonuses to Damage (weapon skills), Toughness (hitpoints) and Pursuit (riding/athletics skills) now carry over proportionally to battles!
  

• Champion's combat skills scale up with Prowess (Prowess*10 by default), can be changed in new Settings.ini in the mod's Module folder after running the mod once.
• Support for CK3-culture men-at-arms specific Banner overrides! You can give regiments like Order Knights unique banners now, per CK3 culture!
• All default configurations/settings are now only generated if no existing configurations are already present! You can safely extract and overwrite the archive now without losing your changes!
  

Using your custom troops
You can either change the base Bannerlord cultures in "Modules\CrusaderBladeTroops\Units\_base_cultures", or you make a copy of the empty_template.xml in "Modules\CrusaderBladeTroops\Units" to create mappings for a specific CK3 culture that overrides the base Bannerlord culture. Open these with Notepad or an equivalent raw text editor. Read the comments inside the XML's for additional explanations. When using troops from other mods, you naturally need to have the troop mod installed and activated as well!

Using your custom Champions
In the same XML files as the troops are entries for Champions. Multiple bannerlord units can be defined for different minimum Prowess levels. You can add as many Prowess levels as you like. Note that the mod also scales up all of a Champion's combat skills with its Prowess (Prowess * 10 by default).

Configurable formation group selection for all CK3 classes!
You can change under which key (1-8) every CK3 troop class is set by
default. Open the following file with a raw text editor like Notepad:

"Modules\CrusaderBladeTroops\Formations\group_numbering.json"

You may put multiple classes under the same key if you want. For advanced users, you can also edit "ck_troop_groups.json" in the folder to add more categories, if for example you want to separate Bowmen from Crossbowmen you can change the right-side of "crossbowmen" from "Archers" to "Crossbows" in that file, and then add a "Crossbows" entry to "group_numbering.json".

Recommended mods for CrusaderBlade
Custom Banners for CrusaderBlade
Realistic Battle Mod (with optional Reduced amount of shoulder shields, my preference at least)
De Re Militari (using this mod's mappings)
Raise your Banner

All of the above work with Bannerlord e1.6.4.