TCS Gear Scale starting point

Can anyone offer some basic guidance on starting points in setting up the Gear Scale in the RPM based TCS settings?
I have TCS working, but at the moment I tend to get not enough intervention in lower gears and a lot of small interventions in higher gears.
I understand the basic principle of having a lower Gear Scale in lower gears, but by what sort of approximate factors (as starting point).
At the moment I have (gear to %):

I can work on the torque reduction map but want to try and have a sensible starting point for the Gear Scale.

Thanks in advance.