Multiple Parallel LED Drivers with Single Thermal Derating NTC Thermistor
A single thermistor is located near the LED's thermal pad.  

Your circuit should work, but you only need one.  Just use the VCC output from one driver, one Radj, a single thermistor, and feed the IADJ of all the drivers.

Because the Iadj is an unbiased input (can be modulated by external voltage source from 0 V to 2.25V), one circuit should work for all the Iadj inputs.

 

This is assuming that all drivers are set to use the same output current. If you need separate current adjustments, then you should consider using a driver with a separate thermal foldback pin like the TPS92510.



TI's LM3414 datasheet has a thermal foldback circuit that will work for you. 

The app note for the LM3414 eval board has a detailed explanation for the circuit values. The LM3414's reference voltage is 1.225V where the TPS92691 is 2.25V.  Use one of the TPS92691's VCC output (pin 16) to power this circuit.