There are occasions where using all TL's might help. An engine failure on finals will require an increase in thrust to maintain speed. This will be true if continuing to land or making a GA. At this point the failed engine has not been identified as A.N.C has kicked in, along with some rudder, and you are still concentrating on the 'A' bit.
Once everything is under control, and time allows, you could identify the AWOL engine, retard the lever, secure if necessary, and continue with confidence that the one('s) left under your hand is (are) good to go.
The same could be true during an engine failure on departure if you decide more thrust is required. Advancing them all, assuming no surge, could solve your perception of too low thrust, then when the problem is solved you can go through the identifying procedure.
However, in today's world i doubt many operators will give you such margins of discretion. It's the same regarding landing OEI with rudder trim ON/OFF. IMHO that's a pilot thing not a company thing. But another topic for another time.