Looks nice I could open it with blender 4.5 LTS and export the .dae. Tells me there might be data loss, but so far it worked fine. I put together the files for a mod and attached it. Can be found in the scenario editor -> actors -> olive_new. So far the 4 meshes are replications, but you can easily substitute them to test however you like. There is also a blank alpha decal_texture, in case you want to add a decal on the ground.  The polycount might be a little high, since each of your branches has 12 tris. On the other hand, this reduces alpha texture display. It's best to compare it to the existing trees, their polycount can be seen in atlas. As long as it doesn't go much higher, it should be fine. If you want, you could gently bake ambient occlusion on the diffuse. For the bark the UV looks a little stretched. You can also use an existing image texture for it, as long as it is licence compatible (preferably CC0), something like this: https://download.blender.org/archive/textures/bark/ Have fun!   olive_tree.zip

Could you check fire damage from Cartha Fire Inf Jav and Iberian Champions Jav Cavalry? Some time ago I read somewhere they actually ignore armor. Edit: also you can check Han crossbows poison damage

Old habits die hard. 

AOM calls it 'Divine Damage', but it's the same thing. I'm not sure it's worth adding another kink to balancing, at least for the base game. It might be nice to add the functionality to the engine for mods. I wouldn't use it in DE though. 

I think the key is to remember that for most (99%) of the game the player will see the tree from a 45 degree angle. So, to give a nice self-shadowing overlapping look, angle the foliage planes flatter (more horizontal or at least at a 45 degree angle) than you normally would. I admit not all trees currently in-game follow this rule precisely, but a the current trees have had a dozen artists over the course of 20 years.