Sliding a gauge behind another one

In the default gauge setup, the two outside gauges slide behind the inside gauge. Is this something that is done in animation to make it look like it’s behind the center gauge, or is it that the center gauge is on top of the other gauges and when the animation moves the outside gauge towards the center it is hidden behind the center gauge in the animation xml?

It is just a order of gauges now they are defined. Gauges are drawn from first to last, so last gauge will be on top of the previous ones.