xrandr help - dual 4K and 1080p monitor setup, can't get scaling to work

Hey all, I can't seem to figure out how to use xrandr to get appropriate scaling for my monitors. I have a primary monitor that is horizontal, in front of me, and is 4K resolution. I have a vertical monitor to the left which is 1080p resolution. By default, everything is super big on the 1080p vertical monitor but things look great on the 4K monitor.

I have followed this video but it does not work, my vertical monitor desktop takes up basically a quarter of the screen and the horizontal monitor gets offset slightly to the right. The command I run is

xrandr --fb 6000x3840 --output HDMI-2 --pos 0x0 --scale 2x2 --output DP-3 --pos 2160x0 --scale 1x1 --primary 

But this does not fix the issue. I am considering just using another 1080p monitor for my horizontal option, but I do really like the 4K option if I can get this to work. Any help would be much appreciated thank you.