Hi guys, I encountered this issue of large armies fighting becoming slideshow as well.
Being a programmer myself, just like to point out that using Afterburner showed that it was a NO LOAD, which only happen in menu or static screen meaning there was nothing to load or no loading of graphics either way. Must be some compilation errors in the codes or something.
Putting it up for the TW team to see this and hopefully can help quickly in the troubleshooting.
I'm running the game on SSD, no mods and my rig has no issue whatsoever.
What is no load limit?
No load limit means that there's nothing for the GPU to do, so it clocked down. Usually happens when not in game or you're on a loading screen or something... and potentially, when a CPU core is pegged
Cheers,