Apparently, Armed Braves receive no defensive bonuses, although they are, just like colonial Soliders, land gunpowder unit, often used for defending native cities. Also, Armed Mounted Braves seem to receive defensive bonuses, while still being mounted unit. Makes no sense considering that regular Mounted Braves or even Dragoons don't get this. Obviously, it should be other way around. Armed Braves with defensive bonuses, and Armed Monted Braves without them. So here is small modpack that fixes this issue. Just put fixed CIV4ProfessionInfos.xml file in your CustomAssets\xml\units folder. Just note that when playing with custom assets locked or when using other mods that this fix will not be applied.