If it's like every other cheap small scale RTR I've ever seen with the integrated Rx/ESC, it's permanently paired to the original Tx.
And of course it won't be compatible with a different Tx/Rx combo, since there's no external signal input on the integrated units to be used as just an ESC.
Binding issue is definitely gonna be one or the other between tx & rx.
I believe those have an integrated rx & ESC, so a new tx/rx combo also means new ESC, and possibly servo if it uses a 5-wire.
Consider the Flysky GT3C. They're a good 3 channel transmitter for the price, have 10 model...