That's the big mistake u made .....first of all changing the team formation u td used the fluidity of the team .second mistake was putting a player on defend . Now rather than two players on support u have one on defending .
What at ur should have done is
after they scored the four goals in first half .
give a very disappointed performance tem talk
than try high tempo with overload and very fluid
direct passing with no work ball in box or retin possession and play through defense
I would have ticked run at defense too
this all would have put more pressure on them keeping the same formation