Yes, I personnally believe that N1, T5, and fuel flow are significant of engine condition and providing they remain within their limitations, they can be mismatched.
In an another hand I have the feeling that the torques resulting from these figures reflect the output power to the gear box and therefore better deserve to be equally balanced.
Our training captain is indeed considering fuel managment first, but the split in fuel cunsumption is never that critical even on long sectors...
This issue is probably not essential since nothing about is in the flight manual, that's also why it is interresting to know others "S76 folks" opinions.