SpeedTree's verts are x8 when in Unity

I've made a very tall tree in SpeedTree which is 9.5k tris at LOD0 (Goes all the way to LOD4 and billboard, I bring the billboards in quite early too), nothing too complex. I was testing a forest of around 40-50 of these trees over a 1km distance and I was getting around 3-5 million verts in Unity.

I am using realtime lighting. I am struggling to understand what is going on, at most I would expect the tree to be 28.5k verts due to it rendering ever single vert on a tri, but currently it seems at LOD0 the tree is rendering at around 80k verts.

I have deferred rendering on. Also at times the verts change massively from 1 mil to 4 mil by moving my camera by 1mm.

What is strange is that it doesn't seem to be affecting my FPS to bad, I am still getting around 150fps in this scene and the batching is under control.

 

The shadow maps also need to be rendered, so if you have 4 cascades, that's another 4 passes.

 

Right I see, is this because the trees are so massive?