Split screen game with up to 4 UI canvases

Hi,

So I have a game with a split screen mode that has four cases:
1 Player Mode - 1 canvas (not scaled)
2 Player Mode - 2 canvases (not scaled)
3 Player Mode - 1 canvas top 50% of the screen (not scaled), 2 canvases scaled to 0.5
4 Player Mode - 4 canvases scaled to 0.5

All canvases consist of a prefab that is used for all 4 players.
I have this working well in 16:9, but if a player has a 16:10 screen, this setup becomes a problem as the canvases are hard wired for 16:9. The moment I start scaling the rect transforms, the anchors stop hitting their marks and I am having trouble figuring out how to make this work.

Has anyone made a split-screen UI setup and could tell me what the ideal setup for something like this is?