Wow this is really looking awesome: I've been looking for a mod like this for a while (I'm a crusader geek definitely).
I have a few gripes...
Only Templar knights wore white: sergeant brothers (in the troop tree they'd be the Templar Brother, Templar Sergeant, Templar Crossbowman, and Templar Sharpshooter) would have black clothing. I have no idea what the chaplain brothers wore, actually.
I have not yet played the game, but IMO the crusader troop tree looks like it needs some work: only the minority of crusaders were Templar, so 'Templar brother' is not a good name idea for the basic troop. It would probably be a good idea to either have the Templar have a fully developed troop tree of their own, or imply make them elite troops; knights mainly, with crossbowmen and footmen as well.
The regular Crusader troop tree also looks like it needs some work. While I can understand from the movie why you'd have the highest troop as a Ibelin knight, it just doesn't make sense logistically; the knights from Ibelin were basic knights. Aside from that, the whole troop tree looks too small, with too little room for many types of troops. Also, I find it strange that you lumped a Knight Hospitaller in with the regular crusaders, while giving the Templar a troop tree of their own. From what I understand, the knights of St. John were an even larger order than the Templar.
Perhaps a troop tree like this could work:
Templar Brother Sergeant
Veteran Knight Templar
Templar Knight Brother
Dismounted Templar Knight
If you wanted to give the Templar a bigger troop selection, you could expand of course, but this would give a better selection more in line with how the Templar troops were.
For the Crusaders, you could try the same, although more expanded. I would suggest that you reserve the light blue surcoat and gold crosses for the highest tier of knight; call them the King's guard or something like that; optional, completely, as I seem to recall that many others besides the royal guard wore those color in KoH. But for visual effect...
I haven't really looked at the other factions (pretty much I searched through the topic until I found the Crusader troop tree, which was what I was looking for, seeing as they'll likely be the only faction I play as.)
Other then those gripes, this is really looking awesome!
What are you doing about coats of arms? I hope you have a good selection of Crusader coats of arms. XP
I'm greatly looking forwards to playing this mod when it comes out in singleplayer.