UTH and Thermostat Question

If I have 3 uth's for my tubs, can I put all 3 on a thermostat? One is a higher wattage but I would use the probe on the lower wattage uth's. The diff in wattage is only 2 watts. Same brand etc. Will that be alright or will it cause issues? The total wattage of all 3 uth's is under the allowed wattage for the thermostat as well.

There are so many variables that any differences can amplify into a big problem even if you use everything exactly the same (I have in my rack) there is still a 4 degree difference from top to bottom. I'd say no, they must be the same to use a single T-stat.