!
All this talk about critical engine is a misnomer.
This is because all the V speeds and emergency proceedures for twins are based on a stated case situation which includes the assumption that the engine that has failed is the critical engine. If the other one fails you have something small in hand, BUT DONT TRY TO REMEMBER WHICH IS WHICH, FLY THE AIRCRAFT.
So as long as you fly the way the whole manual INSTRUCTS you to, it doesn't matter which engine has failed. Except from your trousers point of view.
Read the manual.