Both sigmoid and filmic have contrast adjustments which I tend to use before the modules you have used, but Darktable allows you to choose multiple methods to achieve the desired outcome so I am not saying my methods are better. I never use tone equalizer for contrast adjustment but rather for brightening or darkening parts of the image. I also often use the local contrast module for ‘local contrast’ rather than global contrast. I personally don’t use the sharpen/diffuse local contrast option, but that is just me. I am also not sure if there is any advantage or disadvantage in using contrast adjustment in color balance module rather than filmic or sigmoid. I rarely do contrast in the color balance module since I have usually already done this in filmic or sigmoid. However, if I am in color balance module and feel the need to tweak the contrast I will then play with that slider.
Personally, I use whatever looks good rather than feeling constrained to some recommended pathway. Others may disagree with my approach.