The thing is, when you have a squad full of young, promising and at the same time tactically immature players, having a cozy uncle as manager doesn't work.
You need to have a tactician who hammers in them a philosophy, running paths, attack patterns, etc.
So much so that the young players dream about it at night and it settles in their spinal cord.
You can then shape them gently and lead them on a more personal level.
Wrong manager at the wrong time unfortunately..