[JT118]

A single TX will comfortably deal with your proposed setup; This is mine using 3 Nano`s on 2 TX boards and one AQM board. The timing of data flows are controlled by Werks software for the TX / AQM Nano`s and RX unit.

Sensor Sets:
TX0 On Roof
Temperature:  SHT31 Main T/H Outside Sensor Mapped 0,0 I assume.
                          SHT11 T/H Extra Sensor 0 mapped 0,1
Rain: Tipping Bucket
Wind: Speed Reed switch
Direction: 1Kohm Potentiometer,
Solar: Pyranometer
 
TX 1 On grass
Temperature: SHT11 T/H  Extra Sensor 1 mapped 1,1
One wire Waterproof DS18B20 Soil 1m depth S1 Mapped 1,3
One wire Waterproof DS18B20 Soil 30cm depth S2 Mapped 1,0
One wire Waterproof DS18B20 Soil 10cm depth S3 Mapped 1,1
One wire Waterproof DS18B20 Grass Temp S4 Mapped 1,2
Vegetronix Soil  moisture. S1 mapped 1,0
Decagon Leaf Wetness.     S2 mapped 1,1

AQM:
T/H SHT31 mapped as 8,0
Air Quality sensors CO2 and pm's