Mixed lighting using probes and baked GI vs Realtime lighting with Realtime GI

I am wondering if someone can explain which is the better for performance between these two options, for an outdoor scene with a few hundred objects, many of them just foliage and rocks. But surrounded by huge mountains and large terrains.

1. I use mixed lighting, marking my mountains and other large objects as lightmap static, using baked GI for these. But leaving grass, rocks, and trees (trees dont bake very nicely for some reason) as lightmap dynamic, and instead use probes to get bounces on these objects. Do I even need light probes when using mixed lighting, or is that only for when using purely baked?
   
2. I use Realtime lighting (which I dont really need since my sun is static), and bake everything using realtime GI.

Unfortunately simply baking everything using mixed/baked GI is not possible for me it seems, to reach the results I want I need to use a resolution that crashes unity after a few hours. So I thought option 1 was a clever compromise, but not sure if it will actually make a difference on performance compared to option 2, which is a lot easier to manage.

I have a very bad grasp of how different lighting effect performance, except that baked is better than realtime. But I think in most scenarios it's not that black and white, like in mine.