I looked at your file, you just have to change the Alpha blend value(its in the material settings right under the backface culling setting) to alpha blend, or alpha clip. Right now its set to opaque.
I guess that was a pretty noob-ish mistake then. Thanks very much!
Unfortunately alpha clip makes everything look even more jittery than it did before. Maybe just need to re-do all the grass textures with less narrow anti-aliasing…