Performance issues in Linux

Hi, I play exclusively on Linux, using Proton in Steam, version 4.11-7. When the games progress and there's lots of units on screen, it gets very laggy. Like sub-25 fps, which is laughable given my specs compared to recommended specs, I've got 8 gb ram, an i7 2600k, amd rx 580 8gb and my res is 3440x1440

Are there any performance improvements to be had? I've turned off the 3d water and antialiasing and vsync and stuff.

Should I just dual-boot windows again in order to play?

​

Thanks dudessss