David,
I had prepared a long post, but I decided to cut it short

The measurements I talk about, has been done with professional equipment, measuring the current spikes directly at the batteries (more accurately, at the connector at the receiver, after 30 cm 2 mm2 wires).
The Powerbox Royal is quicker and will show the higher peaks than Weatronic will, hence my feeling that Wea softens/averages the peaks somewhat (HW filter at the ADC, software average or probably some combination of that)
So rest assured, the peaks are much higher than you see from the Wea software!

Still changes nothing about the fact that you will have a higher voltage drop along one single cable with a number of servos on, than compared with a seperare cable to each servo (as well as some kind of fault tolerance)