I once faced a team like that average 19. I am 28. The match started. Possession 70 for me with bonus of 15% possession.
The opponent didn't get any attack until the first half where he got a counter and scored a goal with it.
So I changed my formation to 3-4-3, full pitch pressing, passes by flanks, hard attacking with offside trap.
Well I was getting all of the attack and nothing was being scored until minute 80 where my midfielder scored a goal.
The match ended and I drew. Facing this problem these days so I'm trying to change tactics to see which one fits best.