Well, it's a bit weird. But use 4-1 defending line for his 3ST's, 2 MC's to cover midfield, 2 wings to avoid his 3 central defenders and with 1 ST you have 4-5-1V. This is my advice. Excepting that, the normal tactic to counter 4-1-2-3 it's 4-4-1-1, when the opponent plays with 2 MC's. I would suggest you to go for 4-5-1-V tough.