Hi,
I'm Rodrigo and I'll help you.
On PowerToys, you can use the Fanzy Zones feature, in which you can divide your display zones and drag the windows to create a split screen.
Get PowerToys from the Microsoft Store:
https://apps.microsoft.com/store/detail/XP89DCG...
After installing it, open PowerToys > Fanzy Zones > Launch Layout Editor > Create New Layout > and make your 8 zones layout.
By default, it is set to show the zones when you hold Shift while dragging the window, dropping the window on the desired zone will resize the window.