Considering purchasing 2 Rachio controllers - problem is, I have 17 zones on a Hunter ICC controller today. I’ve read the other comments on this board but not quite sure I understand what is entailed in first hooking up multiple Rachio’s and then how you manage them. How do you make sure they don’t run at the same time, etc. I found the attached picture on Amazon where someone has clearly connected multiple Rachio’s together, but can’t seem to find any instructions on that. Can someone help me?