SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

I am in the process of revitalizing a long dormant and neglected sprinkler system in the house I recently purchased. Right now the controller (hyrdro rain HRH-6) is running 5 zones, 2 in one box and 3 in another. There are 2 C wires attached at the controller, which go into the ground and I'm not sure where from there. I would expect one to go to each valve box, but that doesn't seem to be the case. The box with 2 valves has one C wire coming in connected to both valves, just like I'd expect. Unfortunately, the other one has 3 C wires (maybe 2 incoming and 1 outgoing?). One goes to 2 valves, the other goes to the 3rd valve and then back out of the box.

Any ideas why someone might have set this system up this way? Any reason why I can't just go with a single C wire for all 5 valves? I need to replace a couple of valves anyway, so I'll be doing some digging. Any ideas would be appreciated. Thanks.