Look at the Islanders defensively this year compared to last year. The biggest problem with the Leaf's defensive system isn't the personnel, it's the coaching staff.
I get the point you're trying to make. But lets say the Islanders go out in the 2nd round instead of the first like the leafs did. Does it all really matter? Would you be happy with Babs and the coaching staff if we had a 2nd round exit instead of the first?
Would you also be happy with the product on the ice and our offensive players playing a more sound defensive game and say dropping 25% of their offensive production from previous years?
Does Freddy freeze the puck instead of playing it leading to the first goal in game 7 if we had Trotz?
Does Jake not do the same mistakes we've seen him do since day one even before Babs leading to another goal if we had Trotz?
Do 4 players who look like they are writing on the ice with crayons with the way they were swinging their sticks not happen if we had Trotz?
A part of me agrees with you and what you said. But let's not act like the personnel didn't make their share of the mistakes. I'm pretty sure Babs or any other coach in the world never drawn up any play that led to those mistakes.