The problem is that after that display its not the system we play its the individual overall performance by the players. Some were truly hopeless today!
You're right, this is something which is often overlooked in the desire to find a solution to an abject performance like that. None of our players seemed capable of realising let alone responding when our longball aimless hoof didn't work today, and as the pundit on radio post game said that shouldn't require a prompt or instruction from the touchline at this level.
You can fiddle with formations and shuffle our limited pack as much as you like but if the players play without desire or confidence it isn't changing anything.