It does seem ridiculous to have so many stats. I'm in the radiant heat business and that delivery system lends itself to a lot of stats, so people want them. I don't like high numbers like that because it makes the homeowner program them all or just forget about it and leave them all set without programs.
The Nest system is designed to gather info, through the internet, about each house it is installed in and develop a database The stats notice if people are home and program themselves. This leads to another set of problems, but the thinking is that it can identify problems if the house responds differently than usual and they can notify the homeowner if the bill seems too high, etc. But a lot of it is based on engineers trying to solve problems they really don't understand. And control of the system becomes too complicated for the homeowner.
At least with the "simpler" internet stats, you can see the display on a smart phone and adjust it easily. Not only from miles away, but from upstairs. Still, it's not for me. Simpler is better.
In my house, which is nearing completion, there will be a solar only thermostat next to a programmable thermostat in each zone. Four zones total. The simple digital stats from Lux or Honeywell are reliable and interchangeable between locations if one fails. They'll run, if forgotten, for a number of years on their batteries.
Mulitple zones in a larger house makes sense, setup as you describe for yours. Part of why I started this thread is that dead batteries is the main vulnerability that will stop the digital Honeywell's I've seen - otherwise they seem pretty good.
Many single digital stats don't get programmed, just set to a fixed temperature only. Really a waste in that case, the customer gains nothing from the added complexity of the control.
Radiant heat, that makes sense. A house I had many years ago had electric baseboards - it was nice to have each room at exactly the desired temperature.
I'm liking what I've seen of the mini-splits systems, I might take a serious look at those next time around.
Rgds, D.