I have noticed this each year. Chandikeswara is made to go round the other deities very quickly and taken into the temple. Immediately after this Ganesa sets out at great speed for his circumambulation. But his younger brother Subrahmanya cannot allow that and so he moves out at great speed too. Now that is not so easy for Ganesa is small while Subrahmanya with consorts and peacock is pretty unwieldy as an ensemble and so there is plenty of backing and forwarding, shouting, roaring etc. Subrahmanya beats Ganesa to it and goes around his parents and elder brother.