Things to put in the drag chain.

Ground wire 4mm2 6mm
Spindle cy 4x1.5 mm 9.6mm

Home/stop combined
y/z home switches cy 4x0.75 7.1mm
X1,X2 home switches cy 4x0.75 7.1mm
Bert.
Why do you need a ground wire in the drag chain, also if you want to use cy cable for the switches why not use 3 core 0.5mm. I just have 4 mm air lines in mine and find it ok. You could also use 1.0 mm to the spindle as it is 3 phase and the 2.2kw will be split between the cables.

Just a thought.