Separating Unique Parameters from Firmware Binaries | Interrupt

hi all ,
could be merger(mergehex.exe tool )

Unique Parameter(A.hex) and App (B.hex)

i try to merger (A and B, mergehex -m A.hex B.hex -o C.hex)
ERROR: The hex files cannot be merged since there are conflicts

it seem write other program(python) to rebuild .like " Secure firmware updates with code signing"
or other ?