Great question! I agree with Nigel, and generally match torque in cruise. For takeoff, match whatever is the limit to maximize the total power into the transmission (therefore, I usually match temp for takeoff on warm days, torque on cool days)
Generally, fuel burn rate matches torque, so you keep better fuel balance matching torques in cruise. But again, if you are up against the max cruise temp limit, and speed is what you want, then match temps and hold them both against the 694 cruise limit.