Not sure I'm following you, but you should have two sensors behind the little grille on the rt. wall in front of the RH slide. Remove the screws and you can see them. They go directly to each of the two front roof units. The other sensor is on a BR wall and it goes to the BR roof unit, of course. Then each roof unit has wiring to the stat, of course.
I'm afraid I haven't played around with the Aqua/Hydro Hot enough to tell you what sensors they use...I'm assuming they use the same ones. But the center one is not used, of course-just the front and rear ones.
Bottom line....Those heat pumps are independently controlled (Wired in parallel) and should not operate all together, if that is your question. I will say those sensors do not accurately control temps, however. Not as well as we are used to seeing in our homes, for example. You should also know there is about a 1.75 minute delay built in when changing temps before the unit responds.
2018 Newmar Ventana
2007 Lexus LX470 Toad