> Lets look at the 2 tables and the graph above

It is not a graph of a quansheng battery, is it? Liion batteries use different chemistries (I pointed that 2 times before, you keep ignoring that) and will have different discharge curves. The curve is very flat for the most part and can give huge errors in state of charge value if you use some random curve found on the internet.
1600 uses pouch prismatic cells, 2200 uses cylindricall 18650 cells. I did discharge curves for both and this is what I got. If 2200 curve works better for you, then use that one.

If people can't favm