can i put two thermostats on one zone temporarily

I have two 1 bedroom apts just renovated and now occupied, new radiant system and forgot to pull tstat wire. anyway using honeywells redlink but i suspect because solarization etc each not only will the front and back have different needs but the each apt has a well solarized and a not very solarized room so i have no idea yet where tstat will best work. i would like to give each apt its own visionpro 8000 and remote sensor and use the ability to watch it on internet to see whats happening for a while then decide if i can get away with one location or an average or what. but in the interum i would like either tstat to be able to open the zone valve for that floor manifold, Im hoping i can just twist the wires together and jam them in lol but what happens if the second apt calls while its on etc?

If its pertinent i plan to use the redlink eim for each stat and bring them into the taco expandable zone valve control panel