Balance 710 replacement

So, I have one more question:
We have a HA Balance 710 pair. One of them seems to have a corrupted flash and probably needs replacing.
As the remaining one is HW-2 will it work as a HA pair with a new one with HW-3?

Balance 710 HW-2 will be limited to 6.3.4 firmware and the HW-3 version is different hardware so this would not be recommended.

Thank you for the advice!